Christy Tremonti - University of Wisconsin- Madison

Christy Tremonti
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Name
Christy Tremonti
Affiliation
University of Wisconsin- Madison
City
Madison
Country
United States

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Astrophysics of Galaxies (24)
 
Cosmology and Nongalactic Astrophysics (19)
 
Instrumentation and Methods for Astrophysics (8)
 
Astrophysics (8)
 
High Energy Astrophysical Phenomena (1)

Publications Authored By Christy Tremonti

We study the gas phase metallicity (O/H) and nitrogen abundance gradients traced by star forming regions in a representative sample of 550 nearby galaxies in the stellar mass range $\rm 10^9-10^{11.5} M_\odot$ with resolved spectroscopic data from the SDSS-IV MaNGA survey. Using strong-line ratio diagnostics (R23 and O3N2 for metallicity and N2O2 for N/O) and referencing to the effective (half-light) radius ($\rm R_e$), we find that the metallicity gradient steepens with stellar mass, lying roughly flat among galaxies with $\rm log(M_\star/M_\odot) = 9. Read More

2017Feb
Authors: Michael R. Blanton, Matthew A. Bershady, Bela Abolfathi, Franco D. Albareti, Carlos Allende Prieto, Andres Almeida, Javier Alonso-García, Friedrich Anders, Scott F. Anderson, Brett Andrews, Erik Aquino-Ortíz, Alfonso Aragón-Salamanca, Maria Argudo-Fernández, Eric Armengaud, Eric Aubourg, Vladimir Avila-Reese, Carles Badenes, Stephen Bailey, Kathleen A. Barger, Jorge Barrera-Ballesteros, Curtis Bartosz, Dominic Bates, Falk Baumgarten, Julian Bautista, Rachael Beaton, Timothy C. Beers, Francesco Belfiore, Chad F. Bender, Andreas A. Berlind, Mariangela Bernardi, Florian Beutler, Jonathan C. Bird, Dmitry Bizyaev, Guillermo A. Blanc, Michael Blomqvist, Adam S. Bolton, Médéric Boquien, Jura Borissova, Remco van den Bosch, Jo Bovy, William N. Brandt, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Adam J. Burgasser, Etienne Burtin, Nicolás G. Busca, Michele Cappellari, Maria Leticia Delgado Carigi, Joleen K. Carlberg, Aurelio Carnero Rosell, Ricardo Carrera, Brian Cherinka, Edmond Cheung, Yilen Gómez Maqueo Chew, Cristina Chiappini, Peter Doohyun Choi, Drew Chojnowski, Chia-Hsun Chuang, Haeun Chung, Rafael Fernando Cirolini, Nicolas Clerc, Roger E. Cohen, Johan Comparat, Luiz da Costa, Marie-Claude Cousinou, Kevin Covey, Jeffrey D. Crane, Rupert A. C. Croft, Irene Cruz-Gonzalez, Daniel Garrido Cuadra, Katia Cunha, Guillermo J. Damke, Jeremy Darling, Roger Davies, Kyle Dawson, Axel de la Macorra, Nathan De Lee, Timothée Delubac, Francesco Di Mille, Aleks Diamond-Stanic, Mariana Cano-Díaz, John Donor, Juan José Downes, Niv Drory, Hélion du Mas des Bourboux, Christopher J. Duckworth, Tom Dwelly, Jamie Dyer, Garrett Ebelke, Daniel J. Eisenstein, Eric Emsellem, Mike Eracleous, Stephanie Escoffier, Michael L. Evans, Xiaohui Fan, Emma Fernández-Alvar, J. G. Fernandez-Trincado, Diane K. Feuillet, Alexis Finoguenov, Scott W. Fleming, Andreu Font-Ribera, Alexander Fredrickson, Gordon Freischlad, Peter M. Frinchaboy, Lluís Galbany, R. Garcia-Dias, D. A. García-Hernández, Patrick Gaulme, Doug Geisler, Joseph D. Gelfand, Héctor Gil-Marín, Bruce A. Gillespie, Daniel Goddard, Violeta Gonzalez-Perez, Kathleen Grabowski, Paul J. Green, Catherine J. Grier, James E. Gunn, Hong Guo, Julien Guy, Alex Hagen, ChangHoon Hahn, Matthew Hall, Paul Harding, Sten Hasselquist, Suzanne L. Hawley, Fred Hearty, Jonay I. Gonzalez Hernández, Shirley Ho, David W. Hogg, Kelly Holley-Bockelmann, Jon A. Holtzman, Parker H. Holzer, Joseph Huehnerhoff, Timothy A. Hutchinson, Ho Seong Hwang, Héctor J. Ibarra-Medel, Gabriele da Silva Ilha, Inese I. Ivans, KeShawn Ivory, Kelly Jackson, Trey W. Jensen, Jennifer A. Johnson, Amy Jones, Henrik Jönsson, Eric Jullo, Vikrant Kamble, Karen Kinemuchi, David Kirkby, Francisco-Shu Kitaura, Mark Klaene, Gillian R. Knapp, Jean-Paul Kneib, Juna A. Kollmeier, Ivan Lacerna, Richard R. Lane, Dustin Lang, David R. Law, Daniel Lazarz, Jean-Marc Le Goff, Fu-Heng Liang, Cheng Li, Hongyu LI, Marcos Lima, Lihwai Lin, Yen-Ting Lin, Sara Bertran de Lis, Chao Liu, Miguel Angel C. de Icaza Lizaola, Dan Long, Sara Lucatello, Britt Lundgren, Nicholas K. MacDonald, Alice Deconto Machado, Chelsea L. MacLeod, Suvrath Mahadevan, Marcio Antonio Geimba Maia, Roberto Maiolino, Steven R. Majewski, Elena Malanushenko, Viktor Malanushenko, Arturo Manchado, Shude Mao, Claudia Maraston, Rui Marques-Chaves, Karen L. Masters, Cameron K. McBride, Richard M. McDermid, Brianne McGrath, Ian D. McGreer, Nicolás Medina Peña, Matthew Melendez, Andrea Merloni, Michael R. Merrifield, Szabolcs Meszaros, Andres Meza, Ivan Minchev, Dante Minniti, Takamitsu Miyaji, Surhud More, John Mulchaey, Francisco Müller-Sánchez, Demitri Muna, Ricardo R. Munoz, Adam D. Myers, Preethi Nair, Kirpal Nandra, Janaina Correa do Nascimento, Alenka Negrete, Melissa Ness, Jeffrey A. Newman, Robert C. Nichol, David L. Nidever, Christian Nitschelm, Pierros Ntelis, Julia E. O'Connell, Ryan J. Oelkers, Audrey Oravetz, Daniel Oravetz, Zach Pace, Nelson Padilla, Nathalie Palanque-Delabrouille, Pedro Alonso Palicio, Kaike Pan, Taniya Parikh, Isabelle Pâris, Changbom Park, Alim Y. Patten, Sebastien Peirani, Marcos Pellejero-Ibanez, Samantha Penny, Will J. Percival, Ismael Perez-Fournon, Patrick Petitjean, Matthew M. Pieri, Marc Pinsonneault, Alice Pisani, Radosław Poleski, Francisco Prada, Abhishek Prakash, Anna Bárbara de Andrade Queiroz, M. Jordan Raddick, Anand Raichoor, Sandro Barboza Rembold, Hannah Richstein, Rogemar A. Riffel, Rogério Riffel, Hans-Walter Rix, Annie C. Robin, Constance M. Rockosi, Sergio Rodríguez-Torres, A. Roman-Lopes, Carlos Román-Zúñiga, Margarita Rosado, Ashley J. Ross, Graziano Rossi, John Ruan, Rossana Ruggeri, Eli S. Rykoff, Salvador Salazar-Albornoz, Mara Salvato, Ariel G. Sánchez, David Sánchez Aguado, José R. Sánchez-Gallego, Felipe A. Santana, Basílio Xavier Santiago, Conor Sayres, Ricardo P. Schiavon, Jaderson da Silva Schimoia, Edward F. Schlafly, David J. Schlegel, Donald P. Schneider, Mathias Schultheis, William J. Schuster, Axel Schwope, Hee-Jong Seo, Zhengyi Shao, Shiyin Shen, Matthew Shetrone, Michael Shull, Joshua D. Simon, Danielle Skinner, M. F. Skrutskie, Anže Slosar, Verne V. Smith, Jennifer S. Sobeck, Flavia Sobreira, Garrett Somers, Diogo Souto, David V. Stark, Keivan Stassun, Fritz Stauffer, Matthias Steinmetz, Thaisa Storchi-Bergmann, Alina Streblyanska, Guy S. Stringfellow, Genaro Suárez, Jing Sun, Nao Suzuki, Laszlo Szigeti, Manuchehr Taghizadeh-Popp, Baitian Tang, Charling Tao, Jamie Tayar, Mita Tembe, Johanna Teske, Aniruddha R. Thakar, Daniel Thomas, Benjamin A. Thompson, Jeremy L. Tinker, Patricia Tissera, Rita Tojeiro, Hector Hernandez Toledo, Sylvain de la Torre, Christy Tremonti, Nicholas W. Troup, Octavio Valenzuela, Inma Martinez Valpuesta, Jaime Vargas-González, Mariana Vargas-Magaña, Jose Alberto Vazquez, Sandro Villanova, M. Vivek, Nicole Vogt, David Wake, Rene Walterbos, Yuting Wang, Benjamin Alan Weaver, Anne-Marie Weijmans, David H. Weinberg, Kyle B. Westfall, David G. Whelan, Vivienne Wild, John Wilson, W. M. Wood-Vasey, Dominika Wylezalek, Ting Xiao, Renbin Yan, Meng Yang, Jason E. Ybarra, Christophe Yèche, Nadia Zakamska, Olga Zamora, Pauline Zarrouk, Gail Zasowski, Kai Zhang, Gong-Bo Zhao, Zheng Zheng, Zhi-Min Zhou, Guangtun B. Zhu, Manuela Zoccali, Hu Zou

We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratio in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially-resolved spectroscopy for thousands of nearby galaxies (median redshift of z = 0. Read More

Galactic outflows are believed to play an important role in regulating star formation in galaxies, but estimates of the outflowing mass and momentum have historically been based on uncertain assumptions. Here, we measure the mass, momentum, and energy outflow rates of seven nearby star-forming galaxies using ultraviolet absorption lines and observationally motivated estimates for the density, metallicity, and radius of the outflow. Low-mass galaxies generate outflows faster than their escape velocities with mass outflow rates up to twenty times larger than their star formation rates. Read More

Diffuse Ionized Gas (DIG) is prevalent in star-forming galaxies. Using a sample of 365 nearly face-on star-forming galaxies observed by MaNGA, we demonstrate how DIG in star-forming galaxies impacts the measurements of emission line ratios, hence the interpretation of diagnostic diagrams and gas-phase metallicity measurements. At fixed metallicity, DIG-dominated low H\alpha\ surface brightness regions display enhanced [SII]/H\alpha, [NII]/H\alpha, [OII]/H\beta, and [OI]/H\alpha. Read More

Galaxies grow through both internal and external processes. In about 10% of nearby red galaxies with little star formation, gas and stars are counter-rotating, demonstrating the importance of external gas acquisition in these galaxies. However, systematic studies of such phenomena in blue, star-forming galaxies are rare, leaving uncertain the role of external gas acquisition in driving evolution of blue galaxies. Read More

The nature of warm, ionized gas outside of galaxies may illuminate several key galaxy evolutionary processes. A serendipitous observation by the MaNGA survey has revealed a large, asymmetric H$\alpha$ complex with no optical counterpart that extends $\approx8"$ ($\approx6.3$ kpc) beyond the effective radius of a dusty, starbursting galaxy. Read More

2016Aug
Authors: SDSS Collaboration, Franco D. Albareti, Carlos Allende Prieto, Andres Almeida, Friedrich Anders, Scott Anderson, Brett H. Andrews, Alfonso Aragon-Salamanca, Maria Argudo-Fernandez, Eric Armengaud, Eric Aubourg, Vladimir Avila-Reese, Carles Badenes, Stephen Bailey, Beatriz Barbuy, Kat Barger, Jorge Barrera-Ballesteros, Curtis Bartosz, Sarbani Basu, Dominic Bates, Giuseppina Battaglia, Falk Baumgarten, Julien Baur, Julian Bautista, Timothy C. Beers, Francesco Belfiore, Matthew Bershady, Sara Bertran de Lis, Jonathan C. Bird, Dmitry Bizyaev, Guillermo A. Blanc, Michael Blanton, Michael Blomqvist, Adam S. Bolton, J. Borissova, Jo Bovy, William Nielsen Brandt, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Etienne Burtin, Nicolas G. Busca, Hugo Orlando Camacho Chavez, M. Cano Diaz, Michele Cappellari, Ricardo Carrera, Yanping Chen, Brian Cherinka, Edmond Cheung, Cristina Chiappini, Drew Chojnowski, Chia-Hsun Chuang, Haeun Chung, Rafael Fernando Cirolini, Nicolas Clerc, Roger E. Cohen, Julia M. Comerford, Johan Comparat, Marie-Claude Cousinou, Kevin Covey, Jeffrey D. Crane, Rupert Croft, Katia Cunha, Luiz da Costa, Gabriele da Silva Ilha, Jeremy Darling, James W. Davidson Jr., Kyle Dawson, Nathan De Lee, Axel de la Macorra, Sylvain de la Torre, Alice Deconto Machado, Timothee Delubac, Aleksandar M. Diamond-Stanic, John Donor, Juan Jose Downes, Niv Drory, Helion du Mas des Bourboux, Cheng Du, Tom Dwelly, Garrett Ebelke, Arthur Eigenbrot, Daniel J. Eisenstein, Yvonne P. Elsworth, Eric Emsellem, Michael Eracleous, Stephanie Escoffier, Michael L. Evans, Jesus Falcon-Barroso, Xiaohui Fan, Ginevra Favole, Emma Fernandez-Alvar, J. G. Fernandez-Trincado, Diane Feuillet, Scott W. Fleming, Andreu Font-Ribera, Gordon Freischlad, Peter Frinchaboy, Hai Fu, Yang Gao, D. A. Garcia-Hernandez, Ana E. Garcia Perez, Rafael A. Garcia, R. Garcia-Dias, Patrick Gaulme, Junqiang Ge, Douglas Geisler, Hector Gil Marin, Bruce Gillespie, Leo Girardi, Daniel Goddard, Yilen Gomez Maqueo Chew, Violeta Gonzalez-Perez, Kathleen Grabowski, Paul Green, Catherine J. Grier, Thomas Grier, Hong Guo, Julien Guy, Alex Hagen, Matt Hall, Paul Harding, R. E. Harley, Sten Hasselquist, Suzanne Hawley, Christian R. Hayes, Fred Hearty, Saskia Hekker, Hector Hernandez Toledo, Shirley Ho, David W. Hogg, Kelly Holley-Bockelmann, Jon A. Holtzman, Parker H. Holzer, Jian Hu, Daniel Huber, Timothy Alan Hutchinson, Ho Seong Hwang, Hector J. Ibarra-Medel, Inese I. Ivans, KeShawn Ivory, Kurt Jaehnig, Trey W. Jensen, Jennifer A. Johnson, Amy Jones, Eric Jullo, T. Kallinger, Karen Kinemuchi, David Kirkby, Mark Klaene, Jean-Paul Kneib, Juna A. Kollmeier, Ivan Lacerna, Richard R. Lane, Dustin Lang, Pierre Laurent, David R. Law, Jean-Marc Le Goff, Alexie Leauthaud, Cheng Li, Ran Li, Chen Li, Niu Li, Fu-Heng Liang, Yu Liang, Marcos Lima, Lihwai Lin, Lin Lin, Yen-Ting Lin, Dan Long, Sara Lucatello, Nicholas MacDonald, Chelsea L. MacLeod, J. Ted Mackereth, Suvrath Mahadevan, Marcio Antonio-Geimba Maia, Roberto Maiolino, Steven R. Majewski, Olena Malanushenko, Nicolas Dullius Mallmann, Arturo Manchado, Claudia Maraston, Rui Marques-Chaves, Inma Martinez Valpuesta, Karen L. Masters, Savita Mathur, Ian D. McGreer, Andrea Merloni, Michael R. Merrifield, Szabolcs Meszaros, Andres Meza, Andrea Miglio, Ivan Minchev, Karan Molaverdikhani, Antonio D. Montero-Dorta, Benoit Mosser, Demitri Muna, Adam Myers, Preethi Nair, Kirpal Nandra, Melissa Ness, Jeffrey A. Newman, Robert C. Nichol, David L. Nidever, Christian Nitschelm, Julia O'Connell, Audrey Oravetz, Nelson Padilla, Nathalie Palanque-Delabrouille, Kaike Pan, John Parejko, Isabelle Paris, John A. Peacock, Sebastien Peirani, Marcos Pellejero-Ibanez, Samantha Penny, Will J. Percival, Jeffrey W. Percival, Ismael Perez-Fournon, Patrick Petitjean, Matthew Pieri, Marc H. Pinsonneault, Alice Pisani, Francisco Prada, Abhishek Prakash, Natalie Price-Jones, M. Jordan Raddick, Mubdi Rahman, Anand Raichoor, Sandro Barboza Rembold, A. M. Reyna, James Rich, Hannah Richstein, Jethro Ridl, Rogerio Riffel, Rogemar A. Riffel, Hans-Walter Rix, Annie C. Robin, Constance M. Rockosi, Sergio Rodriguez-Torres, Thaise S. Rodrigues, Natalie Roe, A. Roman Lopes, Carlos Roman-Zuniga, Ashley J. Ross, Graziano Rossi, John Ruan, Rossana Ruggeri, Jessie C. Runnoe, Salvador Salazar-Albornoz, Mara Salvato, Ariel G. Sanchez, Sebastian F. Sanchez, Jose R. Sanchez-Gallego, Basilio Xavier Santiago, Ricardo Schiavon, Jaderson S. Schimoia, Eddie Schlafly, David J. Schlegel, Donald P. Schneider, Ralph Schoenrich, Mathias Schultheis, Axel Schwope, Hee-Jong Seo, Aldo Serenelli, Branimir Sesar, Zhengyi Shao, Matthew Shetrone, Michael Shull, Victor Silva Aguirre, M. F. Skrutskie, Anže Slosar, Michael Smith, Verne V. Smith, Jennifer Sobeck, Garrett Somers, Diogo Souto, David V. Stark, Keivan G. Stassun, Matthias Steinmetz, Dennis Stello, Thaisa Storchi Bergmann, Michael A. Strauss, Alina Streblyanska, Guy S. Stringfellow, Genaro Suarez, Jing Sun, Manuchehr Taghizadeh-Popp, Baitian Tang, Charling Tao, Jamie Tayar, Mita Tembe, Daniel Thomas, Jeremy Tinker, Rita Tojeiro, Christy Tremonti, Nicholas Troup, Jonathan R. Trump, Eduardo Unda-Sanzana, O. Valenzuela, Remco van den Bosch, Mariana Vargas-Magana, Jose Alberto Vazquez, Sandro Villanova, M. Vivek, Nicole Vogt, David Wake, Rene Walterbos, Yuting Wang, Enci Wang, Benjamin Alan Weaver, Anne-Marie Weijmans, David H. Weinberg, Kyle B. Westfall, David G. Whelan, Eric Wilcots, Vivienne Wild, Rob A. Williams, John Wilson, W. M. Wood-Vasey, Dominika Wylezalek, Ting Xiao, Renbin Yan, Meng Yang, Jason E. Ybarra, Christophe Yeche, Fang-Ting Yuan, Nadia Zakamska, Olga Zamora, Gail Zasowski, Kai Zhang, Cheng Zhao, Gong-Bo Zhao, Zheng Zheng, Zheng Zheng, Zhi-Min Zhou, Guangtun Zhu, Joel C. Zinn, Hu Zou

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2, MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. Read More

The MaNGA Survey (Mapping Nearby Galaxies at Apache Point Observatory) is one of three core programs in the Sloan Digital Sky Survey IV. It is obtaining integral field spectroscopy (IFS) for 10K nearby galaxies at a spectral resolution of R~2000 from 3,622-10,354A. The design of the survey is driven by a set of science requirements on the precision of estimates of the following properties: star formation rate surface density, gas metallicity, stellar population age, metallicity, and abundance ratio, and their gradients; stellar and gas kinematics; and enclosed gravitational mass as a function of radius. Read More

To evaluate the impact of stellar feedback, it is critical to estimate the mass outflow rates of galaxies. Past estimates have been plagued by uncertain assumptions about the outflow geometry, metallicity, and ionization fraction. Here we use Hubble Space Telescope ultraviolet spectroscopic observations of the nearby starburst NGC 6090 to demonstrate that many of these quantities can be constrained by the data. Read More

We assemble a sample of disk star-forming galaxies from the Sloan Digital Sky Survey Data Release 7, studying the structure of H$\alpha$ emission lines, finding a large fraction of this sample contains boxy H$\alpha$ line profiles. This fraction depends on galaxy physical and geometric parameters in the following way: (1) it increases monotonically with star formation rate per unit area ($\Sigma_{\rm SFR}$), and stellar mass ($M_*$), with the trend being much stronger with $M_*$, from $\sim$0% at $M_*=10^{10}M_{\odot}$ to about 50% at $M_*=10^{11}M_\odot$; (2) the fraction is much smaller in face-on systems than in edge-on systems. It increases with galaxy inclination ($i$) while $i < 60\,^{\circ}$ and is roughly a constant of 25% beyond this range; (3) for the sources which can be modeled well with two velocity components, blueshifted and redshifted from the systemic velocity, these is a positive correlation between the velocity difference of these two components and the stellar mass, with a slope similar to the Tully-Fisher relation; (4) the two components are very symmetric in the mean, both in velocity and in amplitude. Read More

We study the ionization structure of galactic outflows in 37 nearby, star forming galaxies with the Cosmic Origins Spectrograph on the Hubble Space Telescope. We use the O I, Si II, Si III, and Si IV ultraviolet absorption lines to characterize the different ionization states of outflowing gas. We measure the equivalent widths, line widths, and outflow velocities of the four transitions, and find shallow scaling relations between them and galactic stellar mass and star formation rate. Read More

Mapping Nearby Galaxies at Apache Point Observatory (MaNGA), one of three core programs in the Sloan Digital Sky Survey-IV (SDSS-IV), is an integral-field spectroscopic (IFS) survey of roughly 10,000 nearby galaxies. It employs dithered observations using 17 hexagonal bundles of 2 arcsec fibers to obtain resolved spectroscopy over a wide wavelength range of 3,600-10,300A. To map the internal variations within each galaxy, we need to perform accurate {\it spectral surface photometry}, which is to calibrate the specific intensity at every spatial location sampled by each individual aperture element of the integral field unit. Read More

We present results on gas flows in the halo of a Milky Way-like galaxy at z=0.413 based on high-resolution spectroscopy of a background galaxy. This is the first study of circumgalactic gas at high spectral resolution towards an extended background source (i. Read More

We investigate the supernova-driven galactic wind of the barred spiral galaxy NGC 7552, using both ground-based optical nebular emission lines and far-ultraviolet absorption lines measured with the Hubble Space Telescope Cosmic Origins Spectrograph. We detect broad (~300 km/s) blueshifted (-40 km/s) optical emission lines associated with the galaxy's kpc-scale star-forming ring. The broad line kinematics and diagnostic line ratios suggest that the H-alpha emission comes from clouds of high density gas entrained in a turbulent outflow. Read More

Many astronomers now participate in large international collaborations, and it is important to examine whether these structures foster a scientific climate that is inclusive and diverse. The Committee on the Participation of Women in the Sloan Digital Sky Survey (CPWS) was formed to evaluate the demographics and gender climate within SDSS-IV, one of the largest and most geographically distributed astronomical collaborations. In April 2014, the CPWS administered a demographic survey to establish a baseline for the incipient SDSS-IV. Read More

MaNGA (Mapping Nearby Galaxies at Apache Point Observatory) is a 6-year SDSS-IV survey that will obtain resolved spectroscopy from 3600 $\AA$ to 10300 $\AA$ for a representative sample of over 10,000 nearby galaxies. In this paper, we derive spatially resolved stellar population properties and radial gradients by performing full spectral fitting of observed galaxy spectra from P-MaNGA, a prototype of the MaNGA instrument. These data include spectra for eighteen galaxies, covering a large range of morphological type. Read More

We present an analysis of the data produced by the MaNGA prototype run (P-MaNGA), aiming to test how the radial gradients in recent star formation histories, as indicated by the 4000AA-break (D4000), Hdelta absorption (EW(Hd_A)) and Halpha emission (EW(Ha)) indices, can be useful for understanding disk growth and star formation cessation in local galaxies. We classify 12 galaxies observed on two P-MaNGA plates as either centrally quiescent (CQ) or centrally star-forming (CSF), according to whether D4000 measured in the central spaxel of each datacube exceeds 1.6. Read More

2015Jan
Affiliations: 1Steward Observatory, University of Arizona, 2Argelander-Institut für Astronomie, Universität Bonn, 3Steward Observatory, University of Arizona, 4Steward Observatory, University of Arizona, 5Steward Observatory, University of Arizona, 6Max-Planck-Institut für Astronomie, 7University of Toledo, 8University of Wisconsin- Madison

Post-starburst (or "E+A") galaxies are characterized by low H$\alpha$ emission and strong Balmer absorption, suggesting a recent starburst, but little current star formation. Although many of these galaxies show evidence of recent mergers, the mechanism for ending the starburst is not yet understood. To study the fate of the molecular gas, we search for CO (1-0) and (2-1) emission with the IRAM 30m and SMT 10m telescopes in 32 nearby ($0. Read More

We present an overview of a new integral field spectroscopic survey called MaNGA (Mapping Nearby Galaxies at Apache Point Observatory), one of three core programs in the fourth-generation Sloan Digital Sky Survey (SDSS-IV) that began on 2014 July 1. MaNGA will investigate the internal kinematic structure and composition of gas and stars in an unprecedented sample of 10,000 nearby galaxies. We summarize essential characteristics of the instrument and survey design in the context of MaNGA's key science goals and present prototype observations to demonstrate MaNGA's scientific potential. Read More

To study the effect of supermassive black holes (SMBHs) on their host galaxies it is important to study the hosts when the SMBH is near its peak activity. A method to investigate the host galaxies of high luminosity quasars is to obtain optical spectra at positions offset from the nucleus where the relative contribution of the quasar and host are comparable. However, at these extended radii the galaxy surface brightness is often low (20-22 mag per arcsec$^{2}$) and the resulting spectrum might have such low S/N that it hinders analysis with standard stellar population modeling techniques. Read More

We obtained medium-resolution ultraviolet (UV) spectra between 1150 and 1450 Angstroms of the four UV-bright, infrared (IR)-luminous starburst galaxies IRAS F08339+6517, NGC 3256, NGC 6090, and NGC 7552 using the Cosmic Origins Spectrograph onboard the Hubble Space Telescope. The selected sightlines towards the starburst nuclei probe the properties of the recently formed massive stars and the physical conditions in the starburst-driven galactic superwinds. Despite being metal-rich and dusty, all four galaxies are strong Lyman-alpha emitters with equivalent widths ranging between 2 and 13 Angstroms. Read More

We present a method to estimate the total gas column density, dust-to-gas and dust-to-metal ratios of distant galaxies from rest-frame optical spectra. The technique exploits the sensitivity of certain optical lines to changes in depletion of metals onto dust grains and uses photo-ionization models to constrain these physical ratios along with the metallicity (Z) and dust column density. We compare our gas column density estimates with HI and CO gas mass estimates in nearby galaxies to show that we recover their total gas mass surface density to within a factor of 2 up to a total surface gas mass density of ~75 Mo/pc^2. Read More

We present the design and performance of the multi-object fiber spectrographs for the Sloan Digital Sky Survey (SDSS) and their upgrade for the Baryon Oscillation Spectroscopic Survey (BOSS). Originally commissioned in Fall 1999 on the 2.5-m aperture Sloan Telescope at Apache Point Observatory, the spectrographs produced more than 1. Read More

2012Jul
Affiliations: 1U. of Utah, 2LBNL, 3APC Paris-Diderot, 4LBNL, 5U. of Washington, 6U. of Utah, 7Cutler Group, LP, 8U. of Wisconsin, 9U. of Utah, 10Harvard-Smithsonian CfA, 11Princeton, 12Princeton, 13Princeton, 14Princeton, 15Portsmouth, 16NYU, 17U. of Wyoming, 18U. of Utah, 19Yale Physics, 20IAP Paris, 21Portsmouth, 22IAP Paris, 23UCO/Lick UCSC, 24LBNL, 25Penn State Astronomy, 26U. of Utah, 27Princeton, 28Portsmouth, 29U. of Wisconsin, 30Yale Astronomy, 31NYU, 32U. of Pittsburgh

(abridged) We describe the automated spectral classification, redshift determination, and parameter measurement pipeline in use for the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III (SDSS-III) as of Data Release 9, encompassing 831,000 moderate-resolution optical spectra. We give a review of the algorithms employed, and describe the changes to the pipeline that have been implemented for BOSS relative to previous SDSS-I/II versions, including new sets of stellar, galaxy, and quasar redshift templates. For the color-selected CMASS sample of massive galaxies at redshift 0. Read More

2012Jul
Authors: Kyle S. Dawson, David J. Schlegel, Christopher P. Ahn, Scott F. Anderson, Éric Aubourg, Stephen Bailey, Robert H. Barkhouser, Julian E. Bautista, Alessandra Beifiori, Andreas A. Berlind, Vaishali Bhardwaj, Dmitry Bizyaev, Cullen H. Blake, Michael R. Blanton, Michael Blomqvist, Adam S. Bolton, Arnaud Borde, Jo Bovy, W. N. Brandt, Howard Brewington, Jon Brinkmann, Peter J. Brown, Joel R. Brownstein, Kevin Bundy, N. G. Busca, William Carithers, Aurelio R. Carnero, Michael A. Carr, Yanmei Chen, Johan Comparat, Natalia Connolly, Frances Cope, Rupert A. C. Croft, Antonio J. Cuesta, Luiz N. da Costa, James R. A. Davenport, Timothée Delubac, Roland de Putter, Saurav Dhital, Anne Ealet, Garrett L. Ebelke, Daniel J. Eisenstein, S. Escoffier, Xiaohui Fan, N. Filiz Ak, Hayley Finley, Andreu Font-Ribera, R. Génova-Santos, James E. Gunn, Hong Guo, Daryl Haggard, Patrick B. Hall, Jean-Christophe Hamilton, Ben Harris, David W. Harris, Shirley Ho, David W. Hogg, Diana Holder, Klaus Honscheid, Joe Huehnerhoff, Beatrice Jordan, Wendell P. Jordan, Guinevere Kauffmann, Eyal A. Kazin, David Kirkby, Mark A. Klaene, Jean-Paul Kneib, Jean-Marc Le Goff, Khee-Gan Lee, Daniel C. Long, Craig P. Loomis, Britt Lundgren, Robert H. Lupton, Marcio A. G. Maia, Martin Makler, Elena Malanushenko, Viktor Malanushenko, Rachel Mandelbaum, Marc Manera, Claudia Maraston, Daniel Margala, Karen L. Masters, Cameron K. McBride, Patrick McDonald, Ian D. McGreer, Richard McMahon, Olga Mena, Jordi Miralda-Escudé, Antonio D. Montero-Dorta, Francesco Montesano, Demitri Muna, Adam D. Myers, Tracy Naugle, Robert C. Nichol, Pasquier Noterdaeme, Sebastián E. Nuza, Matthew D. Olmstead, Audrey Oravetz, Daniel J. Oravetz, Russell Owen, Nikhil Padmanabhan, Nathalie Palanque-Delabrouille, Kaike Pan, John K. Parejko, Isabelle Pâris, Will J. Percival, Ismael Pérez-Fournon, Ignasi Pérez-Ràfols, Patrick Petitjean, Robert Pfaffenberger, Janine Pforr, Matthew M. Pieri, Francisco Prada, Adrian M. Price-Whelan, M. Jordan Raddick, Rafael Rebolo, James Rich, Gordon T. Richards, Constance M. Rockosi, Natalie A. Roe, Ashley J. Ross, Nicholas P. Ross, Graziano Rossi, J. A. Rubiño-Martin, Lado Samushia, Ariel G. Sánchez, Conor Sayres, Sarah J. Schmidt, Donald P. Schneider, C. G. Scóccola, Hee-Jong Seo, Alaina Shelden, Erin Sheldon, Yue Shen, Yiping Shu, Anže Slosar, Stephen A. Smee, Stephanie A. Snedden, Fritz Stauffer, Oliver Steele, Michael A. Strauss, Alina Streblyanska, Nao Suzuki, Molly E. C. Swanson, Tomer Tal, Masayuki Tanaka, Daniel Thomas, Jeremy L. Tinker, Rita Tojeiro, Christy A. Tremonti, M. Vargas Magana, Licia Verde, Matteo Viel, David A. Wake, Mike Watson, Benjamin A. Weaver, David H. Weinberg, Benjamin J. Weiner, Andrew A. West, Martin White, W. M. Wood-Vasey, Christophe Yeche, Idit Zehavi, Gong-Bo Zhao, Zheng Zheng

The Baryon Oscillation Spectroscopic Survey (BOSS) is designed to measure the scale of baryon acoustic oscillations (BAO) in the clustering of matter over a larger volume than the combined efforts of all previous spectroscopic surveys of large scale structure. BOSS uses 1.5 million luminous galaxies as faint as i=19. Read More

2012Jul
Authors: SDSS-III Collaboration, :, Christopher P. Ahn, Rachael Alexandroff, Carlos Allende Prieto, Scott F. Anderson, Timothy Anderton, Brett H. Andrews, Éric Aubourg Stephen Bailey, Rory Barnes, Julian Bautista, Timothy C. Beers, Alessandra Beifiori, Andreas A. Berlind, Vaishali Bhardwaj, Dmitry Bizyaev, Cullen H. Blake, Michael R. Blanton, Michael Blomqvist, John J. Bochanski, Adam S. Bolton, Arnaud Borde, Jo Bovy, W. N. Brandt, J. Brinkmann, Peter J. Brown, Joel R. Brownstein, Kevin Bundy, N. G. Busca, William Carithers, Aurelio R. Carnero, Michael A. Carr, Dana I. Casetti-Dinescu, Yanmei Chen, Cristina Chiappini, Johan Comparat, Natalia Connolly, Justin R. Crepp, Stefano Cristiani, Rupert A. C. Croft, Antonio J. Cuesta, Luiz N. da Costa, James R. A. Davenport, Kyle S. Dawson, Roland de Putter, Nathan De Lee, Timothée Delubac, Saurav Dhital, Anne Ealet, Garrett L. Ebelke, Edward M. Edmondson, Daniel J. Eisenstein, S. Escoffier, Massimiliano Esposito, Michael L. Evans, Xiaohui Fan, Bruno Femení a Castellá, Emma Fernández Alvar, Leticia D. Ferreira, N. Filiz Ak, Hayley Finley, Scott W. Fleming, Andreu Font-Ribera, Peter M. Frinchaboy, D. A. García-Hernández, A. E. García Pérez, Jian Ge, R. Génova-Santos, Bruce A. Gillespie, Léo Girardi, Jonay I. González Hernández, Eva K. Grebel, James E. Gunn, Daryl Haggard, Jean-Christophe Hamilton, David W. Harris, Suzanne L. Hawley, Frederick R. Hearty, Shirley Ho, David W. Hogg, Jon A. Holtzman, Klaus Honscheid, J. Huehnerhoff, Inese I. Ivans, Zeljko Ivezić, Heather R. Jacobson, Linhua Jiang, Jonas Johansson, Jennifer A. Johnson, Guinevere Kauffmann, David Kirkby, Jessica A. Kirkpatrick, Mark A. Klaene, Gillian R. Knapp, Jean-Paul Kneib, Jean-Marc Le Goff, Alexie Leauthaud, Khee-Gan Lee, Young Sun Lee, Daniel C. Long, Craig P. Loomis, Sara Lucatello, Britt Lundgren, Robert H. Lupton, Bo Ma, Zhibo Ma, Nicholas MacDonald, Suvrath Mahadevan, Marcio A. G. Maia, Steven R. Majewski, Martin Makler, Elena Malanushenko, Viktor Malanushenko, A. Manchado, Rachel Mandelbaum, Marc Manera, Claudia Maraston, Daniel Margala, Sarah L. Martell, Cameron K. McBride, Ian D. McGreer, Richard G. McMahon, Brice Ménard, Sz. Meszaros, Jordi Miralda-Escudé, Antonio D. Montero-Dorta, Francesco Montesano, Heather L. Morrison, Demitri Muna, Jeffrey A. Munn, Hitoshi Murayama, Adam D. Myers, A. F. Neto, Duy Cuong Nguyen, Robert C. Nichol, David L. Nidever, Pasquier Noterdaeme, Ricardo L. C. Ogando, Matthew D. Olmstead, Daniel J. Oravetz, Russell Owen, Nikhil Padmanabhan, Nathalie Palanque-Delabrouille, Kaike Pan, John K. Parejko, Prachi Parihar, Isabelle Pâris, Petchara Pattarakijwanich, Joshua Pepper, Will J. Percival, Ismael Pérez-Fournon, Ignasi Pérez-Ráfols, Patrick Petitjean, Janine Pforr, Matthew M. Pieri, Marc H. Pinsonneault, G. F. Porto de Mello, Francisco Prada, Adrian M. Price-Whelan, M. Jordan Raddick, Rafael Rebolo, James Rich, Gordon T. Richards, Annie C. Robin, Helio J. Rocha-Pinto, Constance M. Rockosi, Natalie A. Roe, Ashley J. Ross, Nicholas P. Ross, J. A. Rubiño-Martin, Lado Samushia, J. Sanchez Almeida, Ariel G. Sánchez, Basílio Santiago, Conor Sayres, David J. Schlegel, Katharine J. Schlesinger, Sarah J. Schmidt, Donald P. Schneider, Axel D. Schwope, C. G. Scóccola, Uros Seljak, Erin Sheldon, Yue Shen, Yiping Shu, Jennifer Simmerer, Audrey E. Simmons, Ramin A. Skibba, A. Slosar, Flavia Sobreira, Jennifer S. Sobeck, Keivan G. Stassun, Oliver Steele, Matthias Steinmetz, Michael A. Strauss, Molly E. C. Swanson, Tomer Tal, Aniruddha R. Thakar, Daniel Thomas, Benjamin A. Thompson, Jeremy L. Tinker, Rita Tojeiro, Christy A. Tremonti, M. Vargas Magaña, Licia Verde, Matteo Viel, Shailendra K. Vikas, Nicole P. Vogt, David A. Wake, Ji Wang, Benjamin A. Weaver, David H. Weinberg, Benjamin J. Weiner, Andrew A. West, Martin White, John C. Wilson, John P. Wisniewski, W. M. Wood-Vasey, Brian Yanny, Christophe Yèche, Donald G. York, O. Zamora, Gail Zasowski, Idit Zehavi, Gong-Bo Zhao, Zheng Zheng, Guangtun Zhu, Joel C. Zinn

The Sloan Digital Sky Survey III (SDSS-III) presents the first spectroscopic data from the Baryon Oscillation Spectroscopic Survey (BOSS). This ninth data release (DR9) of the SDSS project includes 535,995 new galaxy spectra (median z=0.52), 102,100 new quasar spectra (median z=2. Read More

We present the discovery of compact, obscured star formation in galaxies at z ~ 0.6 that exhibit >1000 km/s outflows. Using optical morphologies from the Hubble Space Telescope and infrared photometry from the Wide-field Infrared Survey Explorer, we estimate star formation rate (SFR) surface densities that approach Sigma_SFR ~ 3000 Msun/yr/kpc^2, comparable to the Eddington limit from radiation pressure on dust grains. Read More

We use principal component analysis (PCA) to estimate stellar masses, mean stellar ages, star formation histories (SFHs), dust extinctions and stellar velocity dispersions for ~290,000 galaxies with stellar masses greater than $10^{11}Msun and redshifts in the range 0.4Read More

2011Jan
Authors: Daniel J. Eisenstein, David H. Weinberg, Eric Agol, Hiroaki Aihara, Carlos Allende Prieto, Scott F. Anderson, James A. Arns, Eric Aubourg, Stephen Bailey, Eduardo Balbinot, Robert Barkhouser, Timothy C. Beers, Andreas A. Berlind, Steven J. Bickerton, Dmitry Bizyaev, Michael R. Blanton, John J. Bochanski, Adam S. Bolton, Casey T. Bosman, Jo Bovy, Howard J. Brewington, W. N. Brandt, Ben Breslauer, J. Brinkmann, Peter J. Brown, Joel R. Brownstein, Dan Burger, Nicolas G. Busca, Heather Campbell, Phillip A. Cargile, William C. Carithers, Joleen K. Carlberg, Michael A. Carr, Yanmei Chen, Cristina Chiappini, Johan Comparat, Natalia Connolly, Marina Cortes, Rupert A. C. Croft, Luiz N. da Costa, Katia Cunha, James R. A. Davenport, Kyle Dawson, Nathan De Lee, Gustavo F. Porto de Mello, Fernando de Simoni, Janice Dean, Saurav Dhital, Anne Ealet, Garrett L. Ebelke, Edward M. Edmondson, Jacob M. Eiting, Stephanie Escoffier, Massimiliano Esposito, Michael L. Evans, Xiaohui Fan, Bruno Femenia Castella, Leticia Dutra Ferreira, Greg Fitzgerald, Scott W. Fleming, Andreu Font-Ribera, Eric B. Ford, Peter M. Frinchaboy, Ana Elia Garcia Perez, B. Scott Gaudi, Jian Ge, Luan Ghezzi, Bruce A. Gillespie, G. Gilmore, Leo Girardi, J. Richard Gott, Andrew Gould, Eva K. Grebel, James E. Gunn, Jean-Christophe Hamilton, Paul Harding, David W. Harris, Suzanne L. Hawley, Frederick R. Hearty, Jonay I. Gonzalez Hernandez, Shirley Ho, David W. Hogg, Jon A. Holtzman, Klaus Honscheid, Naohisa Inada, Inese I. Ivans, Linhua Jiang, Peng Jiang, Jennifer A. Johnson, Cathy Jordan, Wendell P. Jordan, Guinevere Kauffmann, Eyal Kazin, David Kirkby, Mark A. Klaene, Jean-Paul Kneib, G. R. Knapp, C. S. Kochanek, Lars Koesterke, Juna A. Kollmeier, Richard G. Kron, Dustin Lang, James E. Lawler, Jean-Marc Le Goff, Brian L. Lee, Young Sun Lee, Jarron M. Leisenring, Yen-Ting Lin, Jian Liu, Daniel C. Long, Craig P. Loomis, Sara Lucatello, Britt Lundgren, Robert H. Lupton, Bo Ma, Zhibo Ma, Nicholas MacDonald, Claude Mack, Suvrath Mahadevan, Marcio A. G. Maia, Elena Malanushenko, Viktor Malanushenko, Steven R. Majewski, Martin Makler, Rachel Mandelbaum, Claudia Maraston, Daniel Margala, Paul Maseman, Karen L. Masters, Cameron K. McBride, Patrick McDonald, Ian D. McGreer, Richard G. McMahon, Olga Mena Requejo, Brice Menard, Jordi Miralda-Escude, Heather L. Morrison, Fergal Mullally, Demitri Muna, Hitoshi Murayama, Adam D. Myers, Tracy Naugle, Angelo Fausti Neto, Duy Cuong Nguyen, Robert C. Nichol, David L. Nidever, Robert W. O'Connell, Ricardo L. C. Ogando, Matthew D. Olmstead, Daniel J. Oravetz, Nikhil Padmanabhan, Martin Paegert, Nathalie Palanque-Delabrouille, Kaike Pan, Parul Pandey, John K. Parejko, Isabelle Paris, Paulo Pellegrini, Joshua Pepper, Will J. Percival, Patrick Petitjean, Robert Pfaffenberger, Janine Pforr, Stefanie Phleps, Christophe Pichon, Matthew M. Pieri, Francisco Prada, Adrian M. Price-Whelan, M. Jordan Raddick, Beatriz H. F. Ramos, Celine Ryle, I. Neill Reid, James Rich, Gordon T. Richards, George H. Rieke, Marcia J. Rieke, Hans-Walter Rix, Annie C. Robin, Helio J. Rocha-Pinto, Constance M. Rockosi, Natalie A. Roe, Emmanuel Rollinde, Ashley J. Ross, Nicholas P. Ross, Bruno Rossetto, Ariel G. Sanchez, Basilio Santiago, Conor Sayres, Ricardo Schiavon, David J. Schlegel, Katharine J. Schlesinger, Sarah J. Schmidt, Donald P. Schneider, Kris Sellgren, Alaina Shelden, Erin Sheldon, Matthew Shetrone, Yiping Shu, John D. Silverman, Jennifer Simmerer, Audrey E. Simmons, Thirupathi Sivarani, M. F. Skrutskie, Anze Slosar, Stephen Smee, Verne V. Smith, Stephanie A. Snedden, Keivan G. Stassun, Oliver Steele, Matthias Steinmetz, Mark H. Stockett, Todd Stollberg, Michael A. Strauss, Masayuki Tanaka, Aniruddha R. Thakar, Daniel Thomas, Jeremy L. Tinker, Benjamin M. Tofflemire, Rita Tojeiro, Christy A. Tremonti, Mariana Vargas Magana, Licia Verde, Nicole P. Vogt, David A. Wake, Xiaoke Wan, Ji Wang, Benjamin A. Weaver, Martin White, Simon D. M. White, John C. Wilson, John P. Wisniewski, W. Michael Wood-Vasey, Brian Yanny, Naoki Yasuda, Christophe Yeche, Donald G. York, Erick Young, Gail Zasowski, Idit Zehavi, Bo Zhao

Building on the legacy of the Sloan Digital Sky Survey (SDSS-I and II), SDSS-III is a program of four spectroscopic surveys on three scientific themes: dark energy and cosmological parameters, the history and structure of the Milky Way, and the population of giant planets around other stars. In keeping with SDSS tradition, SDSS-III will provide regular public releases of all its data, beginning with SDSS DR8 (which occurred in Jan 2011). This paper presents an overview of the four SDSS-III surveys. Read More

2011Jan
Authors: SDSS-III collaboration, :, Hiroaki Aihara, Carlos Allende Prieto, Deokkeun An, Scott F. Anderson, Éric Aubourg, Eduardo Balbinot, Timothy C. Beers, Andreas A. Berlind, Steven J. Bickerton, Dmitry Bizyaev, Michael R. Blanton, John J. Bochanski, Adam S. Bolton, Jo Bovy, W. N. Brandt, J. Brinkmann, Peter J. Brown, Joel R. Brownstein, Nicolas G. Busca, Heather Campbell, Michael A. Carr, Yanmei Chen, Cristina Chiappini, Johan Comparat, Natalia Connolly, Marina Cortes, Rupert A. C. Croft, Antonio J. Cuesta, Luiz N. da Costa, James R. A. Davenport, Kyle Dawson, Saurav Dhital, Anne Ealet, Garrett L. Ebelke, Edward M. Edmondson, Daniel J. Eisenstein, Stephanie Escoffier, Massimiliano Esposito, Michael L. Evans, Xiaohui Fan, Bruno Femení a Castellá, Andreu Font-Ribera, Peter M. Frinchaboy, Jian Ge, Bruce A. Gillespie, G. Gilmore, Jonay I. González Hernández, J. Richard Gott, Andrew Gould, Eva K. Grebel, James E. Gunn, Jean-Christophe Hamilton, Paul Harding, David W. Harris, Suzanne L. Hawley, Frederick R. Hearty, Shirley Ho, David W. Hogg, Jon A. Holtzman, Klaus Honscheid, Naohisa Inada, Inese I. Ivans, Linhua Jiang, Jennifer A. Johnson, Cathy Jordan, Wendell P. Jordan, Eyal A. Kazin, David Kirkby, Mark A. Klaene, G. R. Knapp, Jean-Paul Kneib, C. S. Kochanek, Lars Koesterke, Juna A. Kollmeier, Richard G. Kron, Hubert Lampeitl, Dustin Lang, Jean-Marc Le Goff, Young Sun Lee, Yen-Ting Lin, Daniel C. Long, Craig P. Loomis, Sara Lucatello, Britt Lundgren, Robert H. Lupton, Zhibo Ma, Nicholas MacDonald, Suvrath Mahadevan, Marcio A. G. Maia, Martin Makler, Elena Malanushenko, Viktor Malanushenko, Rachel Mandelbaum, Claudia Maraston, Daniel Margala, Karen L. Masters, Cameron K. McBride, Peregrine M. McGehee, Ian D. McGreer, Brice Ménard, Jordi Miralda-Escudé, Heather L. Morrison, F. Mullally, Demitri Muna, Jeffrey A. Munn, Hitoshi Murayama, Adam D. Myers, Tracy Naugle, Angelo Fausti Neto, Duy Cuong Nguyen, Robert C. Nichol, Robert W. O'Connell, Ricardo L. C. Ogando, Matthew D. Olmstead, Daniel J. Oravetz, Nikhil Padmanabhan, Nathalie Palanque-Delabrouille, Kaike Pan, Parul Pandey, Isabelle Pâris, Will J. Percival, Patrick Petitjean, Robert Pfaffenberger, Janine Pforr, Stefanie Phleps, Christophe Pichon, Matthew M. Pieri, Francisco Prada, Adrian M. Price-Whelan, M. Jordan Raddick, Beatriz H. F. Ramos, Céline Reylé, James Rich, Gordon T. Richards, Hans-Walter Rix, Annie C. Robin, Helio J. Rocha-Pinto, Constance M. Rockosi, Natalie A. Roe, Emmanuel Rollinde, Ashley J. Ross, Nicholas P. Ross, Bruno M. Rossetto, Ariel G. Sánchez, Conor Sayres, David J. Schlegel, Katharine J. Schlesinger, Sarah J. Schmidt, Donald P. Schneider, Erin Sheldon, Yiping Shu, Jennifer Simmerer, Audrey E. Simmons, Thirupathi Sivarani, Stephanie A. Snedden, Jennifer S. Sobeck, Matthias Steinmetz, Michael A. Strauss, Alexander S. Szalay, Masayuki Tanaka, Aniruddha R. Thakar, Daniel Thomas, Jeremy L. Tinker, Benjamin M. Tofflemire, Rita Tojeiro, Christy A. Tremonti, Jan Vandenberg, M. Vargas Magaña, Licia Verde, Nicole P. Vogt, David A. Wake, Ji Wang, Benjamin A. Weaver, David H. Weinberg, Martin White, Simon D. M. White, Brian Yanny, Naoki Yasuda, Christophe Yeche, Idit Zehavi

The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with new instrumentation and new surveys focused on Galactic structure and chemical evolution, measurements of the baryon oscillation feature in the clustering of galaxies and the quasar Ly alpha forest, and a radial velocity search for planets around ~8000 stars. This paper describes the first data release of SDSS-III (and the eighth counting from the beginning of the SDSS). The release includes five-band imaging of roughly 5200 deg^2 in the Southern Galactic Cap, bringing the total footprint of the SDSS imaging to 14,555 deg^2, or over a third of the Celestial Sphere. Read More

2010Nov
Affiliations: 1Carnegie Observatories, 2Universidad Complutense de Madrid, 3University of Wisconsin-Madison, 4University of Cambridge

A great deal of our understanding of star formation in the local universe has been built upon an extensive foundation of H-alpha observational studies. However, recent work in the ultraviolet (UV) with GALEX has shown that star formation rates (SFRs) inferred from H-alpha in galactic environments characterized by low stellar and gas densities tend to be less than those based on the UV luminosity. The origin of the discrepancy is actively debated because one possible explanation is that the stellar initial mass function is systematically deficient in high mass stars in such environments. Read More

We present 46 rest-frame ultraviolet (UV) spectra of 28 local starburst and star-forming galaxies which were observed with the Faint Object Spectrograph (FOS) and the Goddard High Resolution Spectrograph (GHRS) of the Hubble Space Telescope (HST) at a spectral resolution of a few 100 km/s. We compare the HST spectra with lower resolution International Ultraviolet Explorer (IUE) spectra of the same galaxies and find systematic differences: the bright star clusters targeted in HST's ~1 arcsec apertures provide about 15% of the starburst luminosity traced by IUE's 10 arcsec by 20 arcsec aperture; they are bluer and have stronger stellar-wind features suggesting that the HST apertures have preferentially been placed on the youngest areas of the burst. In contrast, lines arising from the interstellar medium (ISM) show similar equivalent widths in both the large and small aperture observations, suggesting similar ISM properties from larger to smaller scales. Read More

We present results from a GALEX ultraviolet (UV) survey of a complete sample of 390 galaxies within ~11 Mpc of the Milky Way. The UV data are a key component of the composite Local Volume Legacy (LVL), an ultraviolet-to-infrared imaging program designed to provide an inventory of dust and star formation in nearby spiral and irregular galaxies. The ensemble dataset is an especially valuable resource for studying star formation in dwarf galaxies, which comprise over 80% of the sample. Read More

2010Jul
Affiliations: 1UC San Diego, 2U of Cambridge, 3U of Wisconsin-Madison, 4U of Wyoming, 5U of Toledo, 6U of Mass-Amherst

We present intermediate-resolution optical spectrophotometry of 65 galaxies obtained in support of the Spitzer Infrared Nearby Galaxies Survey (SINGS). For each galaxy we obtain a nuclear, circumnuclear, and semi-integrated optical spectrum designed to coincide spatially with mid- and far-infrared spectroscopy from the Spitzer Space Telescope. We make the reduced, spectrophotometrically calibrated one-dimensional spectra, as well as measurements of the fluxes and equivalent widths of the strong nebular emission lines, publically available. Read More

We consider five indicators for intrinsic AGN luminosity: the luminosities of the [OIII]$\lambda$5007 line, the [OIV]25.89$\mu$m line, the mid-infrared (MIR) continuum emission by the torus, and the radio and hard X-ray (E $>$ 10keV) continuum emission. We compare these different proxies using two complete samples of low-redshift type 2 AGN selected in a homogeneous way based on different indicators: an optically selected [OIII] sample and a mid-infrared selected 12$\mu$m sample. Read More

We analyze star forming galaxies drawn from SDSS DR7 to show how the interstellar medium (ISM) Na I 5890, 5896 (Na D) absorption lines depend on galaxy physical properties, and to look for evidence of galactic winds. We combine the spectra of galaxies with similar geometry/physical parameters to create composite spectra with signal-to-noise ~300. The stellar continuum is modeled using stellar population synthesis models, and the continuum-normalized spectrum is fit with two Na I absorption components. Read More

(abridged) Using a complete sample of ~300 star-forming galaxies within 11 Mpc, we evaluate the consistency between star formation rates (SFRs) inferred from the far ultraviolet (FUV) non-ionizing continuum and H-alpha nebular emission, assuming standard conversion recipes in which the SFR scales linearly with luminosity at a given wavelength. Our analysis probes SFRs over 5 orders of magnitude, down to ultra-low activities on the order of ~0.0001 M_sun/yr. Read More

(abridged)The majority of Active Galactic Nuclei (AGN) suffer from significant obscuration by surrounding dust and gas. X-ray surveys in the 2-10 keV band will miss the most heavily-obscured AGN in which the absorbing column density exceeds $\sim10^{24}$cm$^{-2}$ (the Compton-thick AGN). It is therefore vital to know the fraction of AGN that are missed in such X-rays surveys and to determine if these AGN represent some distinct population in terms of the fundamental properties of AGN and/or their host galaxies. Read More

2009Mar
Affiliations: 1Steward Observatory, 2NYU, 3UCSD, 4Steward, 5Steward, 6NYU, 7UCO/Lick, 8UCO/Lick, 9Oxford, 10NOAO, 11NYU, 12Pittsburgh, 13UCO/Lick, 14Maryland, 15MPIA/Wisconsin, 16Steward

Astronomical software is now a fact of daily life for all hands-on members of our community. Purpose-built software for data reduction and modeling tasks becomes ever more critical as we handle larger amounts of data and simulations. However, the writing of astronomical software is unglamorous, the rewards are not always clear, and there are structural disincentives to releasing software publicly and to embedding it in the scientific literature, which can lead to significant duplication of effort and an incomplete scientific record. Read More

Over the last decade optical spectroscopic surveys have characterized the low redshift galaxy population and uncovered populations of star-forming galaxies back to z ~ 7. This work has shown that the primary epoch of galaxy building and black hole growth occurs at redshifts of 2 to 3. The establishment of the concordance LCDM cosmology shifted the focus of galaxy population studies from constraining cosmological parameters to characterizing the processes which regulate the formation and evolution of galaxies. Read More

What is the contribution of mass, metals and energy from starburst galaxies to the Intergalactic Medium? Starburst galaxies drive galactic-scale outflows or "superwinds" that may be responsible for removing metals from galaxies and polluting the Intergalactic Medium (IGM). In the last decade tremendous progress was made in mapping cool entrained gas in superwinds through UV/optical imaging and absorption line spectroscopy. These studies demonstrated that superwinds are ubiquitous in galaxies forming stars at high surface densities and that the most powerful starbursts can drive outflows near escape velocity. Read More

Under the unified model for active galactic nuclei (AGNs), narrow-line (Type 2) AGNs are, in fact, broad-line (Type 1) AGNs but each with a heavily obscured accretion disk. We would therefore expect the optical continuum emission from Type 2 AGN to be composed mainly of stellar light and non-variable on the time-scales of months to years. In this work we probe the spectroscopic variability of galaxies and narrow-line AGNs using the multi-epoch data in the Sloan Digital Sky Survey (SDSS) Data Release 6. Read More

2008Nov
Affiliations: 1University of Arizona, 2University of Arizona, 3University of Arizona, 4University of Arizona, 5University of Arizona
Category: Astrophysics

To obtain an unbiased sample of bright LyA blobs [L(LyA) > 10^43 ergs/s], we have undertaken a blind, wide-field, narrow-band imaging survey in the NOAO Deep Wide Field Survey Bootes field with the Steward Bok-2.3m telescope. After searching over 4. Read More

Using a sample of 57,377 star-forming galaxies drawn from the Sloan Digital Sky Survey, we study the relationship between gas-phase oxygen abundance and environment in the local Universe. We find that there is a strong relationship between metallicity and environment such that more metal-rich galaxies favor regions of higher overdensity. Furthermore, this metallicity-density relation is comparable in strength to the color-density relation along the blue cloud. Read More

2007Jun
Affiliations: 1Steward Observatory, 2New York University, 3Steward Observatory
Category: Astrophysics

Numerical simulations suggest that active galactic nuclei (AGNs) play an important role in the formation of early-type galaxies by expelling gas and dust in powerful galactic winds and quenching star formation. However, the existence of AGN feedback capable of halting galaxy-wide star formation has yet to be observationally confirmed. To investigate this question, we have obtained spectra of 14 post-starburst galaxies at z~0. Read More

We investigate the production of nitrogen in star forming galaxies with ultraviolet (UV) radiation detected by the Galaxy Evolution Explorer Satellite (GALEX). We use a sample of 8,745 GALEX emission line galaxies matched to the Sloan Digital Sky Survey (SDSS) spectroscopic sample. We derive both gas-phase oxygen and nitrogen abundances for the sample, and apply stellar population synthesis models to derive stellar masses and star formation histories of the galaxies. Read More

2006Jun
Affiliations: 1Steward Observatory, University of Arizona, 2Steward Observatory, University of Arizona, 3Steward Observatory, University of Arizona, 4Steward Observatory, University of Arizona
Category: Astrophysics

HST ACS images reveal blue cores in four E+A, or post-starburst, galaxies. Follow-up spectroscopy shows that these cores have LINER spectra. The existence of LINERs, consistent with those in many elliptical galaxies, is yet one more piece of evidence that these post-merger, post-starburst, bulge-dominated galaxies will evolve into normal ellipticals. Read More

We use the ROSAT All Sky Survey (RASS) to study the soft X-ray properties of a homogeneous sample of 46,420 quasars selected from the third data release of the Sloan Digital Sky Survey (SDSS). Optical luminosities, both at rest-frame 2500\AA ($L_{2500}$) and in [OIII] ($L_{[\rm{OIII}]}$) span more than three orders of magnitude, while redshifts range over $0.1Read More