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Stellar Masses From The Candels Survey: The Goods-South And Uds Field, P. Satini, H.C. Ferguson, A Fontana, B. Mobasher, G. Barro, M. Castellano, S.L. Finkelstein, A. Grazian, L.T. Hsu, B. Lee, S.K. Lee, J. Pforr, M. Salvato, T. Wiklind, S. Wuyts, O. Almaini, M.C. Cooper, A. Galametz, B. Weiner, R. Amorin, K. Boutsia, C.J. Conselice, T. Dahlen, M.C. Cooper, Mauro Giavalisco, N.A. Grogin, Y. Guo, N.P. Hathi, D. Kocevski, A.M. Koekemoer, P. Kurczynski, E. Merlin, A. Mortlock, J.A. Newman, D. Paris, L. Pentericci, R. Simons, S.P. Willner
Stellar Masses From The Candels Survey: The Goods-South And Uds Field, P. Satini, H.C. Ferguson, A Fontana, B. Mobasher, G. Barro, M. Castellano, S.L. Finkelstein, A. Grazian, L.T. Hsu, B. Lee, S.K. Lee, J. Pforr, M. Salvato, T. Wiklind, S. Wuyts, O. Almaini, M.C. Cooper, A. Galametz, B. Weiner, R. Amorin, K. Boutsia, C.J. Conselice, T. Dahlen, M.C. Cooper, Mauro Giavalisco, N.A. Grogin, Y. Guo, N.P. Hathi, D. Kocevski, A.M. Koekemoer, P. Kurczynski, E. Merlin, A. Mortlock, J.A. Newman, D. Paris, L. Pentericci, R. Simons, S.P. Willner
Mauro Giavalisco
We present the public release of the stellar mass catalogs for the GOODS-S and UDS fields obtained using some of the deepest near-IR images available, achieved as part of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) project. We combine the effort from ten different teams, who computed the stellar masses using the same photometry and the same redshifts. Each team adopted their preferred fitting code, assumptions, priors, and parameter grid. The com- bination of results using the same underlying stellar isochrones reduces the systematics associated with the fitting code and other choices. Thanks to the availability of different …
Aztec Half Square Degree Survey Of The Shades Fields - Ii. Identifications, Redshifts, And Evidence For Large-Scale Structure, Michał J. Michałowski, J. S. Dunlop, R. J. Ivison, M. Cirasuolo, K. I. Caputi, I. Artexaga, V. Arumugam, J. E. Austermann, E. L. Chapin, S. C. Chapman, K. E. K. Coppin, E. Egami, D. H. Hughes, E. Ibar, A. M. J. Mortier, A. M. Schael, K. S. Scott, I. Smail, T. A. Targett, J. Wagg, Grant Wilson, L. Xu, M. Yun
Aztec Half Square Degree Survey Of The Shades Fields - Ii. Identifications, Redshifts, And Evidence For Large-Scale Structure, Michał J. Michałowski, J. S. Dunlop, R. J. Ivison, M. Cirasuolo, K. I. Caputi, I. Artexaga, V. Arumugam, J. E. Austermann, E. L. Chapin, S. C. Chapman, K. E. K. Coppin, E. Egami, D. H. Hughes, E. Ibar, A. M. J. Mortier, A. M. Schael, K. S. Scott, I. Smail, T. A. Targett, J. Wagg, Grant Wilson, L. Xu, M. Yun
Grant Wilson
The AzTEC 1.1 mm survey of the SCUBA HAlf Degree Extragalactic Survey (SHADES) fields is the largest (0.7 deg2) blank-field millimetre-wavelength survey undertaken to date at a resolution of ~18" and a depth of ~1 mJy. We have used the deep optical-to-radio multi-wavelength data in the SHADES Lockman Hole East and SXDF/UDS fields to obtain galaxy identifications for ~64% (~80% with tentative identifications) of the 148 AzTEC-SHADES 1.1 mm sources, exploiting deep radio and 24 um data complemented by methods based on 8 um flux-density and red optical-infrared (i-K) colour. This unusually high identification rate can be attributed to the …
Color And Stellar Population Gradients In Passively Evolving Galaxies At Z~2 From Hst/Wfc3 Deep Imaging In The Hubble Ultra Deep Field, Yicheng Guo, Mauro Giavalisco, Paolo Cassata, Henry C. Ferguson, Mark Dickinson, Alvio Renzini, Anton Koekemoer, Norman A. Grogin, Casey Papovich, Elena Tundo, Adriano Fontana, Jennifer M. Lotz, Sara Salimbeni
Color And Stellar Population Gradients In Passively Evolving Galaxies At Z~2 From Hst/Wfc3 Deep Imaging In The Hubble Ultra Deep Field, Yicheng Guo, Mauro Giavalisco, Paolo Cassata, Henry C. Ferguson, Mark Dickinson, Alvio Renzini, Anton Koekemoer, Norman A. Grogin, Casey Papovich, Elena Tundo, Adriano Fontana, Jennifer M. Lotz, Sara Salimbeni
Mauro Giavalisco
We report the detection of color gradients in six massive (stellar mass > 10^{10} M_{sun}) and passively evolving (specific SFR < 10^{-11}/yr) galaxies at redshift 1.3
The Resolved Stellar Population In 50 Regions Of M83 From Hst/Wfc3 Early Release Science Observations, Hwihyun Kim, Bradley C. Whitmore, Rupali Chandar, Abhijit Saha, Catherine C. Kaleida, Max Mutchler, Seth H. Cohen, Daniela Calzetti, Robert W. O'Connel, Rogier A. Windhorst, Bruce Balick, Howard E. Bond, C. Marcella Carollo, Michael J. Disney, Michael A. Dopita, Jay A. Frogel, Donald N. B. Hall, Jon A. Holtzman, Randy A. Kimble, Patrick J. Mccarthy, Francesco Paresce, Joe I. Silk, John T. Trauger, Alistair R. Walker, Erick T. Young
The Resolved Stellar Population In 50 Regions Of M83 From Hst/Wfc3 Early Release Science Observations, Hwihyun Kim, Bradley C. Whitmore, Rupali Chandar, Abhijit Saha, Catherine C. Kaleida, Max Mutchler, Seth H. Cohen, Daniela Calzetti, Robert W. O'Connel, Rogier A. Windhorst, Bruce Balick, Howard E. Bond, C. Marcella Carollo, Michael J. Disney, Michael A. Dopita, Jay A. Frogel, Donald N. B. Hall, Jon A. Holtzman, Randy A. Kimble, Patrick J. Mccarthy, Francesco Paresce, Joe I. Silk, John T. Trauger, Alistair R. Walker, Erick T. Young
Daniela Calzetti
We present a multi-wavelength photometric study of ~15,000 resolved stars in the nearby spiral galaxy M83 (NGC5236, D=4.61Mpc) based on Hubble Space Telescope Wide Field Camera 3 observations using four filters: F336W, F438W, F555W, and F814W. We select 50 regions (an average size of 260 pc by 280 pc) in the spiral arm and inter-arm areas of M83, and determine the age distribution of the luminous stellar populations in each region. This is accomplished by correcting for extinction towards each individual star by comparing its colors with predictions from stellar isochrones. We compare the resulting luminosity weighted mean ages of …
Improving The Estimation Of Star Formation Rates And Stellar Population Ages Of High-Redshift Galaxies From Broadband Photometry, Seong-Kook Lee, Henry C. Ferguson, Rachel S. Somerville, Tommy Wiklind, Mauro Giavalisco
Improving The Estimation Of Star Formation Rates And Stellar Population Ages Of High-Redshift Galaxies From Broadband Photometry, Seong-Kook Lee, Henry C. Ferguson, Rachel S. Somerville, Tommy Wiklind, Mauro Giavalisco
Mauro Giavalisco
We explore methods to improve the estimates of star formation rates and mean stellar population ages from broadband photometry of high redshift star-forming galaxies. We use synthetic spectral templates with a variety of simple parametric star formation histories to fit broadband spectral energy distributions. These parametric models are used to infer ages, star formation rates and stellar masses for a mock data set drawn from a hierarchical semi-analytic model of galaxy evolution. Traditional parametric models generally assume an exponentially declining rate of star-formation after an initial instantaneous rise. Our results show that star formation histories with a much more gradual …
The Rising Star-Formation Histories Of Distant Galaxies And Implications For Gas Accretion With Time, Casey Papovich, Steven L. Finkelstein, Henry C. Ferguson, Jennifer M. Lotz, Mauro Giavalisco
The Rising Star-Formation Histories Of Distant Galaxies And Implications For Gas Accretion With Time, Casey Papovich, Steven L. Finkelstein, Henry C. Ferguson, Jennifer M. Lotz, Mauro Giavalisco
Mauro Giavalisco
Distant galaxies show correlations between their current star-formation rates (SFRs) and stellar masses, implying that their star-formation histories (SFHs) are highly similar. Moreover, observations show that the UV luminosities and stellar masses grow from z=8 to 3, implying that the SFRs increase with time. We compare the cosmologically averaged evolution in galaxies at 3 < z < 8 at constant comoving number density, n = 2 x 10^-4 Mpc^-3. This allows us to study the evolution of stellar mass and star formation in the galaxy predecessors and descendants in ways not possible using galaxies selected at constant stellar mass or SFR, quantities that evolve strongly in time. We show that the average SFH of these galaxies increase smoothly from z=8 to 3 as SFR ~ t^alpha with alpha = 1.7 +/- 0.2. This conflicts with assumptions that the SFR is either constant or declines exponentially in time. We show that the stellar mass growth in these galaxies is consistent with this derived SFH. This provides evidence that the slope of the high-mass end of the IMF is approximately Salpeter unless the duty cycle of star formation is much less than unity. We argue that these relations follow from gas accretion (either through accretion or delivered by mergers) coupled with galaxy disk growth under the assumption that the SFR depends on the local gas surface density. This predicts that gas fractions decrease from z=8 to 3 on average as f_gas ~ (1+z)^0.9 for galaxies with this number density. The implied galaxy gas accretion rates at z > 4 are as fast and may even exceed the SFR: this is the "gas accretion epoch". At z < 4 the SFR overtakes the implied gas accretion rate, indicating a period where galaxies consume gas faster than it is acquired. At z < 3, galaxies with this number density depart from these relations implying that star formation and gas accretion are slowed at later times.
Biases And Uncertainties In Physical Parameter Estimates Of Lyman Break Galaxies From Broad-Band Photometry, Seong-Kook Lee, Rafal Idzi, Henry C. Ferguson, Rachel S. Somerville, Tommy Wiklind, Mauro Giavalisco
Biases And Uncertainties In Physical Parameter Estimates Of Lyman Break Galaxies From Broad-Band Photometry, Seong-Kook Lee, Rafal Idzi, Henry C. Ferguson, Rachel S. Somerville, Tommy Wiklind, Mauro Giavalisco
Mauro Giavalisco
We investigate the biases and uncertainties in estimates of physical parameters of high-redshift Lyman break galaxies (LBGs), such as stellar mass, mean stellar population age, and star formation rate (SFR), obtained from broad-band photometry. By combining LCDM hierarchical structure formation theory, semi-analytic treatments of baryonic physics, and stellar population synthesis models, we construct model galaxy catalogs from which we select LBGs at redshifts z ~ 3.4, 4.0, and 5.0. The broad-band spectral energy distributions (SEDs) of these model LBGs are then analysed by fitting galaxy template SEDs derived from stellar population synthesis models with smoothly declining SFRs. We compare the …
Smooth(Er) Stellar Mass Maps In Candels: Constraints On The Longevity Of Clumps In High-Redshift Star-Forming Galaxies, Stijn Wuyts, Natascha M. Förster Schreiber, Reinhard Genzel, Yicheng Guo, Guillermo Barro, Eric F. Bell, Avishai Dekel, Sandra M. Faber, Henry C. Ferguson, Mauro Giavalisco, Norman A. Grogin, Nimish P. Hathi, Kuang-Han Huang, Dale D. Kocevski, Anton M. Koekemoer, David C. Koo, Jennifer Lotz, Dieter Lutz, Elizabeth Mcgrath, Jeffrey A, Newman, David Rosario, Amelie Saintonge, Linda J. Tacconi, Benjamin J. Weiner, Arjen Van Der Wel
Smooth(Er) Stellar Mass Maps In Candels: Constraints On The Longevity Of Clumps In High-Redshift Star-Forming Galaxies, Stijn Wuyts, Natascha M. Förster Schreiber, Reinhard Genzel, Yicheng Guo, Guillermo Barro, Eric F. Bell, Avishai Dekel, Sandra M. Faber, Henry C. Ferguson, Mauro Giavalisco, Norman A. Grogin, Nimish P. Hathi, Kuang-Han Huang, Dale D. Kocevski, Anton M. Koekemoer, David C. Koo, Jennifer Lotz, Dieter Lutz, Elizabeth Mcgrath, Jeffrey A, Newman, David Rosario, Amelie Saintonge, Linda J. Tacconi, Benjamin J. Weiner, Arjen Van Der Wel
Mauro Giavalisco
We perform a detailed analysis of the resolved colors and stellar populations of a complete sample of 323 star-forming galaxies at 0.5 < z < 1.5, and 326 star-forming galaxies at 1.5 < z < 2.5 in the ERS and CANDELS-Deep region of GOODS-South. Galaxies were selected to be more massive than 10^10 Msun and have specific star formation rates above 1/t_H. We model the 7-band optical ACS + near-IR WFC3 spectral energy distributions of individual bins of pixels, accounting simultaneously for the galaxy-integrated photometric constraints available over a longer wavelength range. We analyze variations in rest-frame color, stellar surface mass density, age, and extinction as a function of galactocentric radius and local surface brightness/density, and measure structural parameters on luminosity and stellar mass maps. We find evidence for redder colors, older stellar ages, and increased dust extinction in the nuclei of galaxies. Big star-forming clumps seen in star formation tracers are less prominent or even invisible on the inferred stellar mass distributions. Off-center clumps contribute up to ~20% to the integrated SFR, but only 7% or less to the integrated mass of all massive star-forming galaxies at z ~ 1 and z ~ 2, with the fractional contributions being a decreasing function of wavelength used to select the clumps. The stellar mass profiles tend to have smaller sizes and M20 coefficients, and higher concentration and Gini coefficients than the light distribution. Our results are consistent with an inside-out disk growth scenario with brief (100 - 200 Myr) episodic local enhancements in star formation superposed on the underlying disk. Alternatively, the young ages of off-center clumps may signal inward clump migration, provided this happens efficiently on the order of an orbital timescale.