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Modeling The Effects Of Star Formation Histories On Halpha And Ultra-Violet Fluxes In Nearby Dwarf Galaxies, Daniel R. Weisz, Benjamin D. Johnson, L. Clifton Johnson, Evan D. Skillman, Janice C. Lee, Robert C. Kennicutt Jr., Daniela Calzetti, Liese Van Zee, Matthew S. Bothwell, Julianne J. Dalcanton, Daniel A. Dale, Benjamin F. Williams
Modeling The Effects Of Star Formation Histories On Halpha And Ultra-Violet Fluxes In Nearby Dwarf Galaxies, Daniel R. Weisz, Benjamin D. Johnson, L. Clifton Johnson, Evan D. Skillman, Janice C. Lee, Robert C. Kennicutt Jr., Daniela Calzetti, Liese Van Zee, Matthew S. Bothwell, Julianne J. Dalcanton, Daniel A. Dale, Benjamin F. Williams
Daniela Calzetti
We consider the effects of non-constant star formation histories (SFHs) on Halpha and GALEX far ultra-violet (FUV) star formation rate (SFR) indicators. Under the assumption of a fully populated Chabrier IMF, we compare the distribution of Halpha-to-FUV flux ratios from ~ 1500 simple, periodic model SFHs with observations of 185 galaxies from the Spitzer Local Volume Legacy survey. We find a set of SFH models that are well matched to the data, such that more massive galaxies are best characterized by nearly constant SFHs, while low mass systems experience bursts amplitudes of ~ 30 (i.e., an increase in the SFR …
Deep Near-Infrared Spectroscopy Of Passively Evolving Galaxies At Z & 1.4^1, M. Onodera, A. Renzini, M. Carollo, M. Cappellari, C. Mancini, V. Strazzullo, E. Daddi, N. Arimoto, R. Gobat, Y. Yamada, H. J. Mccracken, O. Ilbert, P. Capak, A. Cimatti, Mauro Giavalisco, M. Giavalisco, A. M. Koekemoer, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sanders, N. Scoville, N. Tamura, Y. Taniguchi
Deep Near-Infrared Spectroscopy Of Passively Evolving Galaxies At Z & 1.4^1, M. Onodera, A. Renzini, M. Carollo, M. Cappellari, C. Mancini, V. Strazzullo, E. Daddi, N. Arimoto, R. Gobat, Y. Yamada, H. J. Mccracken, O. Ilbert, P. Capak, A. Cimatti, Mauro Giavalisco, M. Giavalisco, A. M. Koekemoer, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sanders, N. Scoville, N. Tamura, Y. Taniguchi
Mauro Giavalisco
We present the results of new near-IR spectroscopic observations of passive galaxies at z & 1.4 in a concentration of BzK-selected galaxies in the COSMOS field. The observations have been conducted with Subaru/ MOIRCS, and have resulted in absorption lines and/or continuum detection for 18 out of 34 objects. This allows us to measure spectroscopic redshifts for a sample that is almost complete to KAB = 21. COSMOS photometric redshifts are found in fair agreement overall with the spectroscopic redshifts, with a standard deviation of ∼ 0.05; however, ∼ 30% of objects have photometric redshifts systematically underestimated by up to …
Goods-Herschel: An Infrared Main Sequence For Star-Forming Galaxies, D. Elbaz, M. Dickinson, H. S. Hwang, T. Díaz-Santos, G. Magdis, B. Magnelli, D. Le Borgne, F. Galliano, M. Pannella, P. Chanial, L. Armus, V. Charmandaris, E. Daddi, H. Aussel, P. Popesso, J. Kartaltepe, B. Altieri, I. Valtchanov, D. Coia, H. Dannerbauer, K. Dasyra, R. Leiton, J. Mazzarella, D. M. Alexander, V. Buat, D. Burgarella, R-R. Chary, R. Gilli, R. J. Ivison, S. Juneau, E. Le Floc'h, D. Lutz, G. E. Morrison, J. R. Mullaney, E. Murphy, A. Pope, D. Scott, M. Brodwin, D. Calzetti, C. Cesarsky, S. Charlot, H. Dole, P. Eisenhardt, H. C. Ferguson, N. Förster Schreiber, D. Frayer, Mauro Giavalisco, M. Huynh, A. M. Koekemoer, C. Papovich, N. Reddy, C. Surace, H. Teplitz, M. S. Yun, G. Wilson
Goods-Herschel: An Infrared Main Sequence For Star-Forming Galaxies, D. Elbaz, M. Dickinson, H. S. Hwang, T. Díaz-Santos, G. Magdis, B. Magnelli, D. Le Borgne, F. Galliano, M. Pannella, P. Chanial, L. Armus, V. Charmandaris, E. Daddi, H. Aussel, P. Popesso, J. Kartaltepe, B. Altieri, I. Valtchanov, D. Coia, H. Dannerbauer, K. Dasyra, R. Leiton, J. Mazzarella, D. M. Alexander, V. Buat, D. Burgarella, R-R. Chary, R. Gilli, R. J. Ivison, S. Juneau, E. Le Floc'h, D. Lutz, G. E. Morrison, J. R. Mullaney, E. Murphy, A. Pope, D. Scott, M. Brodwin, D. Calzetti, C. Cesarsky, S. Charlot, H. Dole, P. Eisenhardt, H. C. Ferguson, N. Förster Schreiber, D. Frayer, Mauro Giavalisco, M. Huynh, A. M. Koekemoer, C. Papovich, N. Reddy, C. Surace, H. Teplitz, M. S. Yun, G. Wilson
Mauro Giavalisco
We present the deepest far-IR observations obtained with Herschel and examine the 3-500um SEDs of galaxies at 03x10^10 Lsun kpc^-2) and a high specific SFR (i.e., SBs). The rest-frame, UV-2700A size of these distant SBs is typically half that of MS galaxies, supporting the correlation between star formation density and SB activity that is measured for the local sample. Locally, (U)LIRGs are systematically in the SB mode, whereas most distant (U)LIRGs form stars in the "normal" MS mode. This confusion between two modes of star formation is the cause of the so-called "mid-IR excess" population of galaxies found at z …
The Emission By Dust And Stars Of Nearby Galaxies In The Herschel Kingfish Survey, Ramin A. Skibba, Charles W. Engelbracht, Daniel Dale, Joannah Hinz, Stefano Zibetti, Alison Crocker, Brent Groves, Leslie Hunt, Benjamin D. Johnson, Sharon Meidt, Eric J. Murphy, Philip Appleton, Lee Armus, Alberto Bolatto, Bernhard Brandl, Daniela Calzetti, Kevin Croxall, Maud Galametz, Karl. D. Gordon, Robert C. Kennicutt, Jin Koda, Oliver Krause, Edward Montiel, Hans-Walter Rix, Hélène Roussel, Karin Sandstrom, Marc Sauvage, Eva Schinnerer, J. D. Smith, Fabian Walter, Christine D. Wilson, Mark Wolfire
The Emission By Dust And Stars Of Nearby Galaxies In The Herschel Kingfish Survey, Ramin A. Skibba, Charles W. Engelbracht, Daniel Dale, Joannah Hinz, Stefano Zibetti, Alison Crocker, Brent Groves, Leslie Hunt, Benjamin D. Johnson, Sharon Meidt, Eric J. Murphy, Philip Appleton, Lee Armus, Alberto Bolatto, Bernhard Brandl, Daniela Calzetti, Kevin Croxall, Maud Galametz, Karl. D. Gordon, Robert C. Kennicutt, Jin Koda, Oliver Krause, Edward Montiel, Hans-Walter Rix, Hélène Roussel, Karin Sandstrom, Marc Sauvage, Eva Schinnerer, J. D. Smith, Fabian Walter, Christine D. Wilson, Mark Wolfire
Daniela Calzetti
Using new far-infrared imaging from the Herschel Space Observatory with ancillary data from ultraviolet to submillimeter wavelengths, we estimate the total emission from dust and stars of 62 nearby galaxies in the KINGFISH survey in a way that is as empirical and model-independent as possible. We collect and exploit these data in order to measure from the spectral energy distributions (SEDs) precisely how much stellar radiation is intercepted and re-radiated by dust, and how this quantity varies with galaxy properties. By including SPIRE data, we are more sensitive to emission from cold dust grains than previous analyses at shorter wavelengths, …
A Z=1.82 Analog Of Local Ultra-Massive Elliptical Galaxies, M Onodera, E Daddi, R Gobat, M Cappellari, N Arimoto, A Renzini, Y Yamada, Hj Mccracken, C Mancini, P Capak, M Carollo, A Cimatti, M Giavalisco, O Ilbert, X Kong, S Lilly, K Motohara, K Ohta, Db Sanders, N Scoville, N Tamura, Y Taniguchi
A Z=1.82 Analog Of Local Ultra-Massive Elliptical Galaxies, M Onodera, E Daddi, R Gobat, M Cappellari, N Arimoto, A Renzini, Y Yamada, Hj Mccracken, C Mancini, P Capak, M Carollo, A Cimatti, M Giavalisco, O Ilbert, X Kong, S Lilly, K Motohara, K Ohta, Db Sanders, N Scoville, N Tamura, Y Taniguchi
Astronomy Department Faculty Publication Series
We present observations of a very massive galaxy at z = 1.82 that show that its morphology, size, velocity dispersion, and stellar population properties are fully consistent with those expected for passively evolving progenitors of today's giant ellipticals. These findings are based on a deep optical rest-frame spectrum obtained with the Multi-Object InfraRed Camera and Spectrograph on the Subaru Telescope of a high-z passive galaxy candidate (pBzK) from the COSMOS field, for which we accurately measure its redshift of z = 1.8230 and obtain an upper limit on its velocity dispersion σ⋆ < 326 km s−1. By detailed stellar population modeling of both the galaxy broadband spectral energy distribution and the rest-frame optical spectrum, we derive a star formation-weighted age and formation redshift of tsf ≃ 1–2 Gyr and z …
The Nature Of Submillimetre Galaxies In Cosmological Hydrodynamic Simulations, R Dave, K Finlator, Bd Oppenheimer, M Fardal, N Katz, D Keres, Dh Weinberg
The Nature Of Submillimetre Galaxies In Cosmological Hydrodynamic Simulations, R Dave, K Finlator, Bd Oppenheimer, M Fardal, N Katz, D Keres, Dh Weinberg
Astronomy Department Faculty Publication Series
We study the nature of rapidly star-forming galaxies at z= 2 in cosmological hydrodynamic simulations, and compare their properties to observations of submillimetre galaxies (SMGs). We identify simulated SMGs as the most rapidly star-forming systems that match the observed number density of SMGs. In our models, SMGs are massive galaxies sitting at the centres of large potential wells, being fed by smooth infall and gas-rich satellites at rates comparable to their star formation rates (SFRs). They are not typically undergoing major mergers that significantly boost their quiescent SFR, but they still often show complex gas morphologies and kinematics. Our …
Mid-Infrared Spectroscopy Of Candidate Active Galactic Nuclei-Dominated Submillimeter Galaxies, K Coppin, A Pope, K Menendez-Delmestre, Dm Alexander, Js Dunlop, E Egami, J Gabor, E Ibar, Rj Ivison, Je Austermann, Aw Blain, Sc Chapman, Dl Clements, L Dunne, S Dye, D Farrah, Dh Hughes, Amj Mortier, Mj Page, M Rowan-Robinson, D Scott, C Simpson, I Smail, Am Swinbank, M Vaccari, Min Yun
Mid-Infrared Spectroscopy Of Candidate Active Galactic Nuclei-Dominated Submillimeter Galaxies, K Coppin, A Pope, K Menendez-Delmestre, Dm Alexander, Js Dunlop, E Egami, J Gabor, E Ibar, Rj Ivison, Je Austermann, Aw Blain, Sc Chapman, Dl Clements, L Dunne, S Dye, D Farrah, Dh Hughes, Amj Mortier, Mj Page, M Rowan-Robinson, D Scott, C Simpson, I Smail, Am Swinbank, M Vaccari, Min Yun
Astronomy Department Faculty Publication Series
Spitzer spectroscopy has revealed that 80% of submm galaxies (SMGs) are starburst (SB)-dominated in the mid-infrared. Here we focus on the remaining 20% that show signs of harboring powerful active galactic nuclei (AGNs). We have obtained Spitzer-InfraRed Spectrograph spectroscopy of a sample of eight SMGs that are candidates for harboring powerful AGNs on the basis of IRAC color selection (S 8 μm/S 4.5 μm>2, i.e., likely power-law mid-infrared spectral energy distributions). SMGs with an AGN dominating (50%) their mid-infrared emission could represent the "missing link" sources in an evolutionary sequence involving a major merger. First …
Origins Of The Extragalactic Background At 1mm From A Combined Analysis Of The Aztec And Mambo Data In Goods-N, Kyle Penner, Alexandra Pope, Edward L. Chapin, Thomas R. Greve, Frank Bertoldi, Mark Brodwin, Ranga-Ram Chary, Christopher J, Conselice, Kristen Coppin, Mauro Giavalisco, David H. Hughes, Rob J. Ivison, Thushara Perera, Douglas Scott, Kimberly Scott, Grant Wilson
Origins Of The Extragalactic Background At 1mm From A Combined Analysis Of The Aztec And Mambo Data In Goods-N, Kyle Penner, Alexandra Pope, Edward L. Chapin, Thomas R. Greve, Frank Bertoldi, Mark Brodwin, Ranga-Ram Chary, Christopher J, Conselice, Kristen Coppin, Mauro Giavalisco, David H. Hughes, Rob J. Ivison, Thushara Perera, Douglas Scott, Kimberly Scott, Grant Wilson
Mauro Giavalisco
We present a study of the cosmic infrared background, which is a measure of the dust obscured activity in all galaxies in the Universe. We venture to isolate the galaxies responsible for the background at 1mm; with spectroscopic and photometric redshifts we constrain the redshift distribution of these galaxies. We create a deep 1.16mm map (sigma ~ 0.5mJy) by combining the AzTEC 1.1mm and MAMBO 1.2mm datasets in GOODS-N. This combined map contains 41 secure detections, 13 of which are new. By averaging the 1.16mm flux densities of individually undetected galaxies with 24um flux densities > 25uJy, we resolve 31--45 per …
A Spectroscopic Search For Leaking Lyman Continuum At Z~0.7, Carrie R. Bridge, Harry I. Teplitz, Brian Siana, Claudia Scarlata, Christopher J. Conselice, Henry C. Ferguson, Thomas M. Brown, Mara Salvato, Gwen C. Rudie, Duilia F. De Mello, James Colbert, Jonathan P. Gardner, Mauro Giavalisco, Lee Armus
A Spectroscopic Search For Leaking Lyman Continuum At Z~0.7, Carrie R. Bridge, Harry I. Teplitz, Brian Siana, Claudia Scarlata, Christopher J. Conselice, Henry C. Ferguson, Thomas M. Brown, Mara Salvato, Gwen C. Rudie, Duilia F. De Mello, James Colbert, Jonathan P. Gardner, Mauro Giavalisco, Lee Armus
Mauro Giavalisco
We present the results of rest-frame, UV slitless spectroscopic observations of a sample of 32 z~0.7 Lyman break galaxy (LBG) analogs in the COSMOS field. The spectroscopic search was performed with the Solar Blind Channel (SBC) on Hubble Space Telescope. We report the detection of leaking Lyman continuum (LyC) radiation from an AGN-starburst composite. While we find no direct detections of LyC emission in the remainder of our sample, we achieve individual lower limits (3 sigma) of the observed non-ionizing UV to LyC flux density ratios, f_{nu}(1500A)/f_{nu}(830A) of 20 to 204 (median of 73.5) and 378.7 for the stack. Assuming …
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 Bright End Of The Z ~ 7 Uv Luminosity Function From A Wide And Deep Hawk-I Survey, M. Castellano, A. Fontana, D. Paris, A. Grazian, L. Pentericci, K. Boutsia, P. Santini, V. Testa, M. Dickinson, Mauro Giavalisco, R. Bouwens, J.-G. Cuby, F. Mannucci, B. Clément, S. Cristiani, F. Fiore, S. Gallozzi, E. Giallongo, R. Maiolino, N. Menci, A. Moorwood, N. Nonino, A. Renzini, P. Rosati, S. Salimbeni, E. Vanzella
The Bright End Of The Z ~ 7 Uv Luminosity Function From A Wide And Deep Hawk-I Survey, M. Castellano, A. Fontana, D. Paris, A. Grazian, L. Pentericci, K. Boutsia, P. Santini, V. Testa, M. Dickinson, Mauro Giavalisco, R. Bouwens, J.-G. Cuby, F. Mannucci, B. Clément, S. Cristiani, F. Fiore, S. Gallozzi, E. Giallongo, R. Maiolino, N. Menci, A. Moorwood, N. Nonino, A. Renzini, P. Rosati, S. Salimbeni, E. Vanzella
Mauro Giavalisco
(Abridged) We present here the second half of an ESO Large Programme, which exploits the unique combination of area and sensitivity provided in the near-IR by the camera Hawk-I at the VLT. We have obtained - 30 observing hours with Hawk-I in the Y-band of two high galactic latitude fields. We combined the Y-band data with deep J and K Hawk-I observations, and with FORS1/FORS2 U, B, V, R, I, and Z observations to select z-drop galaxies having Z - Y > 1, no optical detection and flat Y - J and Y - K colour terms. We detect 8 high-quality …
A Critical Analysis Of The Uv Luminosity Function At Redshift~7 From Deep Wfc3 Data, A. Grazian, M. Castellano, A. M. Koekemoer, A. Fontana, L. Pentericci, V. Testa, K. Boutsia, E. Giallongo, Mauro Giavalisco, P. Santini
A Critical Analysis Of The Uv Luminosity Function At Redshift~7 From Deep Wfc3 Data, A. Grazian, M. Castellano, A. M. Koekemoer, A. Fontana, L. Pentericci, V. Testa, K. Boutsia, E. Giallongo, Mauro Giavalisco, P. Santini
Mauro Giavalisco
The study of the Luminosity Function (LF) of Lyman Break Galaxies (LBGs) at z=7 is important for ascertaining their role in the reionization of the Universe. We perform a detailed and critical analysis of the statistical and systematic errors in the z~7 LF determination: we have assembled a large sample of candidate LBGs at z~7 from different surveys, spanning a large variety of areas and depths. In particular, we have combined data from the deep (J<27.4) and ultradeep (J<29.2) surveys recently acquired with the new WFC3 NIR camera on HST, over the GOODS-ERS and the HUDF fields, with ground based surveys in wide and shallow areas from VLT and Subaru. We have used public ACS images in the z-band to select z-dropout galaxies, and other public data both in the blue (BVI) and in the red bands to reject possible low-redshift interlopers. We have compared our results with extensive simulations to quantify the observational effects of our selection criteria as well as the effects of photometric scatter, color selections or the morphology of the candidates. We have found that the number density of faint LBGs at z~7 is only marginally sensitive to the color selection adopted, but it is strongly dependent from the assumption made on the half light distributions of the simulated galaxies, used to correct the observed sample for incompleteness. The slope of the faint end of the LBGs LF has thus a rather large uncertainty, due to the unknown distribution of physical sizes of the z~7 LBGs. We conclude that galaxies at z~7 are unable to reionize the Universe unless there is a significant evolution in the clumpiness of the IGM or in the escape fraction of ionising photons or, alternatively, there is a large population of z~7 LBGs with large physical dimensions but still not detected by the present observations.
A Z=1.82 Analog Of Local Ultra-Massive Elliptical Galaxies, M. Onodera, E. Daddi, R. Gobat, M. Cappellari, N. Arimoto, A. Renzini, Y. Yamada, H. J. Mccracken, C. Mancini, P. Capak, M. Carollo, A. Cimatti, Mauro Giavalisco, O. Ilbert, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sanders, N. Scoville, N. Tamura, Y. Taniguchi
A Z=1.82 Analog Of Local Ultra-Massive Elliptical Galaxies, M. Onodera, E. Daddi, R. Gobat, M. Cappellari, N. Arimoto, A. Renzini, Y. Yamada, H. J. Mccracken, C. Mancini, P. Capak, M. Carollo, A. Cimatti, Mauro Giavalisco, O. Ilbert, X. Kong, S. Lilly, K. Motohara, K. Ohta, D. B. Sanders, N. Scoville, N. Tamura, Y. Taniguchi
Mauro Giavalisco
We present observations of a very massive galaxy at z=1.82 which show that its morphology, size, velocity dispersion and stellar population properties that are fully consistent with those expected for passively evolving progenitors of today's giant ellipticals. These findings are based on a deep optical rest-frame spectrum obtained with the Multi-Object InfraRed Camera and Spectrograph (MOIRCS) on the Subaru telescope of a high-z passive galaxy candidate (pBzK) from the COSMOS field, for which we accurately measure its redshift of z=1.8230 and obtain an upper limit on its velocity dispersion sigma_star<326 km/s. By detailed stellar population modeling of both the galaxy broad-band SED and the rest-frame optical spectrum we derive a star-formation-weighted age and formation redshift of t_sf~1-2 Gyr and z_form~2.5-4, and a stellar mass of M_star~(3-4)x10^{11} M_sun. This is in agreement with a virial mass limit of M_vir<7x10^{11}M_sun, derived from the measured sigma_star value and stellar half-light radius, as well as with the dynamical mass limit based on the Jeans equations. In contrast with previously reported super-dense passive galaxies at z~2, the present galaxy at z=1.82 appears to have both size and velocity dispersion similar to early-type galaxies in the local Universe with similar stellar mass. This suggests that z~2 massive and passive galaxies may exhibit a wide range of properties, then possibly following quite different evolutionary histories from z~2 to z=0.
A Detailed Study Of Photometric Redshifts For Goods-South Galaxies, Tomas Dahlen, Bahram Mobasher, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Norman A. Grogin, Yicheng Guo, Anton Koekemoer, Kyoung-Soo Lee, Seong-Kook Lee, Mario Nonino, Adam G. Reiss, Sara Salimbeni
A Detailed Study Of Photometric Redshifts For Goods-South Galaxies, Tomas Dahlen, Bahram Mobasher, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Norman A. Grogin, Yicheng Guo, Anton Koekemoer, Kyoung-Soo Lee, Seong-Kook Lee, Mario Nonino, Adam G. Reiss, Sara Salimbeni
Mauro Giavalisco
We use the deepest and the most comprehensive photometric data currently available for GOODS-South galaxies to measure their photometric redshifts. The photometry includes VLT/VIMOS (U-band), HST/ACS (F435W, F606W, F775W, and F850LP bands), VLT/ISAAC (J-, H-, and Ks-bands), and four Spitzer/IRAC channels (3.6, 4.5, 5.8, and 8.0 micron). The catalog is selected in the z-band (F850LP) and photometry in each band is carried out using the recently completed TFIT algorithm, which performs PSF matched photometry uniformly across different instruments and filters, despite large variations in PSFs and pixel scales. Photometric redshifts are derived using the GOODZ code, which is based on …
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.
The Great Observatories Origins Deep Survey: Constraints On The Lyman Continuum Escape Fraction Distribution Of Lyman--Break Galaxies At 3.4, E. Vanzella, Mauro Giavalisco, A. Inoue, M. Nonino, F. Fontanot, S. Cristiani, A. Grazian, M. Dickinson, D. Stern, P. Tozzi, E. Giallongo, H. Ferguson, H. Spinrad, K. Boutsia, A. Fontana, P. Rosati
The Great Observatories Origins Deep Survey: Constraints On The Lyman Continuum Escape Fraction Distribution Of Lyman--Break Galaxies At 3.4, E. Vanzella, Mauro Giavalisco, A. Inoue, M. Nonino, F. Fontanot, S. Cristiani, A. Grazian, M. Dickinson, D. Stern, P. Tozzi, E. Giallongo, H. Ferguson, H. Spinrad, K. Boutsia, A. Fontana, P. Rosati
Mauro Giavalisco
We use ultra-deep ultraviolet VLT/VIMOS intermediate-band and VLT/FORS1 narrow-band imaging in the GOODS Southern field to derive limits on the distribution of the escape fraction (f_esc) of ionizing radiation for L >~ L*(z=3) Lyman Break Galaxies (LBGs) at redshift 3.4--4.5. Only one LBG, at redshift z=3.795, is detected in its Lyman continuum (LyC; S/N~5.5), the highest redshift galaxy currently known with a direct detection. Its ultraviolet morphology is quite compact (R_eff=0.8, kpc physical). Three out of seven AGN are also detected in their LyC, including one at redshift z=3.951 and z850 = 26.1. From stacked data (LBGs) we set an …
Deep 1.1 Mm-Wavelength Imaging Of The Goods-S Field By Aztec/Aste - I. Source Catalogue And Number Counts, Ks Scott, Min Yun, Gw Wilson, Je Austermann, E Aguilar, I Aretxaga, H Ezawa, D Ferrusca, B Hatsukade, Dh Hughes, D Iono, M Giavalisco, R Kawabe, K Kohno, Pd Mauskopf, T Oshima, Ta Perera, J Rand, Y Tamura, T Tosaki, M Velazquez, Cc Williams, M Zeballos
Deep 1.1 Mm-Wavelength Imaging Of The Goods-S Field By Aztec/Aste - I. Source Catalogue And Number Counts, Ks Scott, Min Yun, Gw Wilson, Je Austermann, E Aguilar, I Aretxaga, H Ezawa, D Ferrusca, B Hatsukade, Dh Hughes, D Iono, M Giavalisco, R Kawabe, K Kohno, Pd Mauskopf, T Oshima, Ta Perera, J Rand, Y Tamura, T Tosaki, M Velazquez, Cc Williams, M Zeballos
Astronomy Department Faculty Publication Series
We present the first results from a confusion-limited map of the Great Observatories Origins Deep Survey-South (GOODS-S) taken with the AzTEC camera on the Atacama Submillimeter Telescope Experiment. We imaged a field to a 1σ depth of 0.48–0.73 mJy beam−1, making this one of the deepest blank-field surveys at mm-wavelengths ever achieved. Although by traditional standards our GOODS-S map is extremely confused due to a sea of faint underlying sources, we demonstrate through simulations that our source identification and number counts analyses are robust, and the techniques discussed in this paper are relevant for other deeply confused surveys. …
Evidence Of A Fast Evolution Of The Uv Luminosity Function Beyond Redshift 6 From A Deep Hawk-I Survey Of The Goods-S Field, M Castellano, A Fontana, K Boutsia, A Grazian, L Pentericci, R Bouwens, M Dickinson, M Giavalisco, P Santini, S Cristiani, Et. Al.
Evidence Of A Fast Evolution Of The Uv Luminosity Function Beyond Redshift 6 From A Deep Hawk-I Survey Of The Goods-S Field, M Castellano, A Fontana, K Boutsia, A Grazian, L Pentericci, R Bouwens, M Dickinson, M Giavalisco, P Santini, S Cristiani, Et. Al.
Astronomy Department Faculty Publication Series
No abstract provided.
The Unusual N Iv]-Emitter Galaxy Gds J033218.92-275302.7: Star Formation Or Agn-Driven Winds From A Massive Galaxy At Z=5.56, E Vanzella, A Grazian, M Hayes, L Pentericci, D Schaerer, M Dickinson, S Cristiani, M Giavalisco, A Verhamme, M Nonino, P Rosati
The Unusual N Iv]-Emitter Galaxy Gds J033218.92-275302.7: Star Formation Or Agn-Driven Winds From A Massive Galaxy At Z=5.56, E Vanzella, A Grazian, M Hayes, L Pentericci, D Schaerer, M Dickinson, S Cristiani, M Giavalisco, A Verhamme, M Nonino, P Rosati
Astronomy Department Faculty Publication Series
Aims. We investigate the nature of the source GDS J033218.92-275302.7 at redshift 5.56.
Methods. The spectral energy distribution of the source is well-sampled by 16 bands photometry from UV-optical (HST and VLT), near infrared, near infrared (VLT) to mid-infrared (Spitzer). The detection of a signal in the mid-infrared Spitzer/IRAC bands 5.8, 8.0 - where the nebular emission contribution is less effective - suggests that there is a Balmer break, the signature of an underlying stellar population formed at earlier epochs. The high-quality VLT/FORS2 spectrum shows a clear Ly emission line, together with semi-forbidden N IV] 1483.3-1486.5 also …
Aztec Half Square Degree Survey Of The Shades Fields - I. Maps, Catalogues And Source Counts, Je Austermann, Min Yun, Et. Al.
Aztec Half Square Degree Survey Of The Shades Fields - I. Maps, Catalogues And Source Counts, Je Austermann, Min Yun, Et. Al.
Astronomy Department Faculty Publication Series
We present the first results from the largest deep extragalactic mm-wavelength survey undertaken to date. These results are derived from maps covering over 0.7 deg2, made at λ= 1.1 mm, using the AzTEC continuum camera mounted on the James Clerk Maxwell Telescope. The maps were made in the two fields originally targeted at λ= 850 μm with the Submillimetre Common-User Bolometer Array (SCUBA) in the SCUBA Half-Degree Extragalactic Survey (SHADES) project, namely the Lockman Hole East (mapped to a depth of 0.9–1.3 mJy rms) and the Subaru/XMM–Newton Deep Field (mapped to a depth of 1.0–1.7 mJy rms). …
The Redshift Search Receiver Observations Of 12co J = 1 → 0 In 29 Ultraluminous Infrared Galaxies, Aeree Chung, Gopal Naraynan, Min S. Yun, Mark Heyer, Neal R. Erickson
The Redshift Search Receiver Observations Of 12co J = 1 → 0 In 29 Ultraluminous Infrared Galaxies, Aeree Chung, Gopal Naraynan, Min S. Yun, Mark Heyer, Neal R. Erickson
Neal Erickson
We present 12CO J=1-->0 observations of ultraluminous infrared galaxies (ULIRGs) obtained using the Redshift Search Receiver (RSR) on the 14-m telescope of the Five College Radio Astronomy Observatory. The RSR is a novel, dual-beam, dual-polarization receiver equipped with an ultra-wideband spectrometer backend that is being built as a facility receiver for the Large Millimeter Telescope. Our sample consists of 29 ULIRGs in the redshift range of 0.04-0.11, including 10 objects with no prior 12CO measurements. We have detected 27 systems (a detection rate of 93%), including 9 ULIRGs that are detected in CO for the first time. Our study …
Star Formation And Mass Assembly In High Redshift Galaxies, P. Santini, A. Fontana, A. Grazian, S. Salimbeni, F. Fiore, F. Fontanot, K. Boutsia, M. Castellano, S. Cristiani, C. De Santis, S. Gallozzi, E. Giallongo, N. Menci, M. Nonino, D. Paris, L. Pentericci, E. Vanzella
Star Formation And Mass Assembly In High Redshift Galaxies, P. Santini, A. Fontana, A. Grazian, S. Salimbeni, F. Fiore, F. Fontanot, K. Boutsia, M. Castellano, S. Cristiani, C. De Santis, S. Gallozzi, E. Giallongo, N. Menci, M. Nonino, D. Paris, L. Pentericci, E. Vanzella
Astronomy Department Faculty Publication Series
Aims. The goal of this work is to infer the star formation properties and the mass assembly process of high redshift (0.3 ≤ z < 2.5) galaxies from their IR emission using the 24 μm band of MIPS-Spitzer. Methods. We used an updated version of the GOODS-MUSIC catalog, which has multiwavelength coverage from 0.3 to 24 μm and either spectroscopic or accurate photometric redshifts.We describe how the catalog has been extended by the addition of mid-IR fluxes derived from theMIPS 24 μm image.We compared two different estimators of the star formation rate (SFR hereafter). One is the total infrared emission derived from 24 μm, estimated using both synthetic and empirical IR templates. The other one is a multiwavelength fit to the full galaxy SED, which automatically accounts for dust reddening and age–star formation activity degeneracies. For both estimates, we computed the SFR density and the specific SFR. Results. We show that the two SFR indicators are roughly consistent, once the uncertainties involved are taken into account. However, they show a systematic trend, IR-based estimates exceeding the fit-based ones as the star formation rate increases. With this new catalog, we show that: a) at z > 0.3, the star formation rate is correlated well with stellar mass, and this relationship seems to steepen with redshift if one relies on IR–based estimates of the SFR; b) the contribution to the global SFRD by massive galaxies increases with redshift up to ≃ 2.5, more rapidly than for galaxies of lower mass, but appears to flatten at higher z; c) despite this increase, the most important contributors to the SFRD at any z are galaxies …
Structural Properties Of Central Galaxies In Groups And Clusters, Yc Guo, Dh Mcintosh, Hj Mo, N Katz, Fc Van Den Bosch, M Weinberg, Sm Weinmann, A Pasquali, Xh Yang
Structural Properties Of Central Galaxies In Groups And Clusters, Yc Guo, Dh Mcintosh, Hj Mo, N Katz, Fc Van Den Bosch, M Weinberg, Sm Weinmann, A Pasquali, Xh Yang
Astronomy Department Faculty Publication Series
Using a statistically representative sample of 911 central galaxies (CENs) from the Sloan Digital Sky Survey (SDSS) Data Release 4 group catalogue, we study how the structure (shape and size) of the first rank (by stellar mass) group and cluster members depends on (1) galaxy stellar mass (Mstar), (2) the global environment defined by the dark matter halo mass (Mhalo) of the host group and (3) the local environment defined by their special halocentric position. We quantify the structure of SDSS galaxies with a galfit-based pipeline that fits two-dimensional Sérsic models to the r-band image data. Through tests with simulated …
Dust-Corrected Star Formation Rates Of Galaxies. I. Combinations Of H Alpha And Infrared Tracers, Rc Kennicutt, Cn Hao, D Calzetti, J Moustakas, Da Dale, G Bendo, Cw Engelbracht, Bd Johnson, Jc Lee
Dust-Corrected Star Formation Rates Of Galaxies. I. Combinations Of H Alpha And Infrared Tracers, Rc Kennicutt, Cn Hao, D Calzetti, J Moustakas, Da Dale, G Bendo, Cw Engelbracht, Bd Johnson, Jc Lee
Astronomy Department Faculty Publication Series
We combine Hα emission-line and infrared (IR) continuum measurements of two samples of nearby galaxies to derive dust attenuation-corrected star formation rates (SFRs). We use a simple energy balance based method that has been applied previously to H II regions in the Spitzer Infrared Nearby Galaxies Survey, and extend the methodology to integrated measurements of galaxies. We find that our composite Hα + IR based SFRs are in excellent agreement with attenuation-corrected SFRs derived from integrated spectrophotometry, over the full range of SFRs (0.01-80 M sun yr-1) and attenuations (0-2.5 mag) studied. We find that the combination of Hα and …
Hubble Space Telescope/Advanced Camera For Surveys Morphology Of Ly Alpha Emitters At Redshift 5.7 In The Cosmos Field, Y Taniguchi, Et. Al.
Hubble Space Telescope/Advanced Camera For Surveys Morphology Of Ly Alpha Emitters At Redshift 5.7 In The Cosmos Field, Y Taniguchi, Et. Al.
Astronomy Department Faculty Publication Series
We present detailed morphological properties of Lyα emitters (LAEs) at z ≈ 5.7 in the COSMOS field based on Hubble Space Telescope Advanced Camera for Surveys (ACS) data. The ACS imaging in the F814W filter covered 85 LAEs of the 119 LAEs identified in the full two square degree field, and 47 LAEs of them are detected in the ACS images. Nearly half of them are spatially extended with a size larger than 0.15 arcsec (∼0.88 kpc at z = 5.7) and up to 0.4 arcsec (∼2.5 kpc at z = 5.7). The others are nearly unresolved compact objects. Two …
Expanding The Search For Galaxies At Z Similar To 7-10 With New Nicmos Parallel Fields, Alaina L. Henry, Brian Siana, Matthew A. Malkan, Matthew L.N. Ashby, Carrie R. Bridge, Ranga-Ram Chary, James W. Colbert, Mauro Giavalisco, Harry I. Teplitz, Patrick J. Mccarthy
Expanding The Search For Galaxies At Z Similar To 7-10 With New Nicmos Parallel Fields, Alaina L. Henry, Brian Siana, Matthew A. Malkan, Matthew L.N. Ashby, Carrie R. Bridge, Ranga-Ram Chary, James W. Colbert, Mauro Giavalisco, Harry I. Teplitz, Patrick J. Mccarthy
Astronomy Department Faculty Publication Series
We have carried out a search for galaxies at z ∼ 7–10 in ∼14.4 arcmin2 of new NICMOS parallel imaging taken in the Great Observatories Origins Deep Survey (5.9 arcmin2), the Cosmic Origins Survey (7.2 arcmin2), and SSA22 (1.3 arcmin2). These images reach 5σ sensitivities of J110 = 26.0–27.5 (AB), and combined they increase the amount of deep near-infrared data by more than 60% in fields where the investment in deep optical data has already been made. We find no z > 7 candidates in our survey area, consistent with the Bouwens et al. measurements at z ∼ 7 and …
Biases And Uncertainties In Physical Parameter Estimates Of Lyman Break Galaxies From Broadband Photometry, Sk Lee, R Idzi, Hc Ferguson, Rs Somerville, T Wiklind, M Giavalisco
Biases And Uncertainties In Physical Parameter Estimates Of Lyman Break Galaxies From Broadband Photometry, Sk Lee, R Idzi, Hc Ferguson, Rs Somerville, T Wiklind, M Giavalisco
Astronomy Department Faculty Publication Series
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 broadband photometry. These biases arise from the simplifying assumptions often used in fitting the spectral energy distributions (SEDs). By combining ΛCDM hierarchical structure formation theory, semianalytic 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 broadband photometric SEDs of these model LBGs are then analyzed by fitting galaxy template …
The Aztec/Sma Interferometric Imaging Survey Of Submillimeter-Selected High-Redshift Galaxies, Jd Younger, Gg Fazio, Js Huang, Min Yun, Gw Wilson, Mln Ashby, Ma Gurwell, Ab Peck, Gr Petitpas, Dj Wilner, Dh Hughes, I Aretxaga, S Kim, Ks Scott, J Austermann, T Perera, Jd Lowenthal
The Aztec/Sma Interferometric Imaging Survey Of Submillimeter-Selected High-Redshift Galaxies, Jd Younger, Gg Fazio, Js Huang, Min Yun, Gw Wilson, Mln Ashby, Ma Gurwell, Ab Peck, Gr Petitpas, Dj Wilner, Dh Hughes, I Aretxaga, S Kim, Ks Scott, J Austermann, T Perera, Jd Lowenthal
Astronomy Department Faculty Publication Series
We present results from a continuing interferometric survey of high-redshift submillimeter galaxies (SMGs) with the Submillimeter Array, including high-resolution (beam size ~2 arcsec) imaging of eight additional AzTEC 1.1 mm selected sources in the COSMOS field, for which we obtain six reliable (peak signal-to-noise ratio (S/N) >5 or peak S/N >4 with multiwavelength counterparts within the beam) and two moderate significance (peak S/N >4) detections. When combined with previous detections, this yields an unbiased sample of millimeter-selected SMGs with complete interferometric follow up. With this sample in hand, we (1) empirically confirm the radio-submillimeter association, (2) examine the submillimeter morphology—including …
The Relative Abundance Of Compact And Normal Massive Early-Type Galaxies And Its Evolution From Redshift Z~2 To The Present, P. Cassata, Mauro Giavalisco, Yicheng Guo, A. Renzini, H. Ferguson, A. M. Koekemoer, S. Salimbeni, C. Scarlata, N. A. Grogin, C. J. Conselice, T. Dahlen, J. M. Lotz, M. Dickinson, Lihwai Lin
The Relative Abundance Of Compact And Normal Massive Early-Type Galaxies And Its Evolution From Redshift Z~2 To The Present, P. Cassata, Mauro Giavalisco, Yicheng Guo, A. Renzini, H. Ferguson, A. M. Koekemoer, S. Salimbeni, C. Scarlata, N. A. Grogin, C. J. Conselice, T. Dahlen, J. M. Lotz, M. Dickinson, Lihwai Lin
Mauro Giavalisco
We report on the evolution of the number density and size of early-type galaxies from z~2 to z~0. We select a sample of 563 massive (M>10^{10} Msun), passively evolving (SSFR<10^{-2} Gyr^{-1}) and morphologically spheroidal galaxies at 01.2 and z<1.2, respectively). We measure a significant evolution of the mass-size relation of early-type galaxies, with the fractional increment that is almost independent on the stellar mass. Early-type galaxies (ETGs) formed at z>1 appear to be preferentially small, and the evolution of the mass-size relation at z<1 is driven by both the continuous size growth of the compact galaxies and the appearance of new ETGs with large sizes. We also find that the number density of all passive early-type galaxies increases rapidly, by a factor of 5, from z~2 to z~1, and then more mildly by another factor of 1.5 from z~1 to z~0. We interpret these results as the evidence that the bulk of the ETGs are formed at 1
Candels: The Contribution Of The Observed Galaxy Population To Cosmic Reionization, Steven L. Finkelstein, Casey Papovich, Russel E, Ryan Jr., Andreas H. Pawlik, Mark Dickinson, Henry C. Ferguson, Kristian Finlator, Anton M. Koekemoer, Mauro Giavalisco, Mauro Giavalisco, Asantha Cooray, James S. Dunlop, Sandy M. Faber, Norman A. Grogin, Dale D. Kocevski, Jeffrey A. Newman
Candels: The Contribution Of The Observed Galaxy Population To Cosmic Reionization, Steven L. Finkelstein, Casey Papovich, Russel E, Ryan Jr., Andreas H. Pawlik, Mark Dickinson, Henry C. Ferguson, Kristian Finlator, Anton M. Koekemoer, Mauro Giavalisco, Mauro Giavalisco, Asantha Cooray, James S. Dunlop, Sandy M. Faber, Norman A. Grogin, Dale D. Kocevski, Jeffrey A. Newman
Mauro Giavalisco
We present measurements of the specific ultraviolet luminosity density from a sample of 483 galaxies at 6 . z . 8. These galaxies were selected from new deep near-infrared Hubble Space Telescope imaging from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey, Hubble UltraDeep Field 2009 and WFC3 Early Release Science programs. In contrast to the majority of previous analyses, which assume that the distribution of galaxy ultraviolet (UV) luminosities follows a Schechter distribution, and that the distribution continues to luminosities far below our observable limit, we investigate the contribution to reionization from galaxies which we can observe, free from …