Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
-
- University of Louisville (59)
- San Jose State University (35)
- Smith College (22)
- Case Western Reserve University (17)
- University of Kentucky (7)
-
- Nova Southeastern University (5)
- Georgia Southern University (3)
- Embry-Riddle Aeronautical University (2)
- Florida Institute of Technology (2)
- Illinois Wesleyan University (2)
- University of Texas Rio Grande Valley (2)
- Bryn Mawr College (1)
- Calvin University (1)
- Dartmouth College (1)
- Macalester College (1)
- University of North Dakota (1)
- West Chester University (1)
- Publication Year
- Publication
-
- Faculty and Staff Scholarship (59)
- Faculty Publications (34)
- Astronomy: Faculty Publications (22)
- Faculty Scholarship (17)
- Physics and Astronomy Faculty Publications (7)
-
- Chemistry and Physics Faculty Articles (5)
- Physics & Astronomy: Faculty Publications (3)
- Aerospace, Physics, and Space Science Faculty Publications (2)
- Physics & Astronomy Faculty Publications (2)
- Publications (2)
- Scholarship (2)
- Dartmouth Scholarship (1)
- Faculty Research, Scholarly, and Creative Activity (1)
- Macalester Journal of Physics and Astronomy (1)
- Physics & Engineering Faculty Publications (1)
- Physics Faculty Publications (1)
- Physics Faculty Research and Scholarship (1)
- University Faculty Publications and Creative Works (1)
- Publication Type
Articles 91 - 120 of 162
Full-Text Articles in Astrophysics and Astronomy
The Sizes Of Candidate Z~9-10 Galaxies : Confirmation Of The Bright Candels Sample And Relation With Luminosity And Mass., Benne W. Holwerda, R. J. Bouwens, P. A. Oesch, R. Smit, G. D. Illingworth, I. Labbe
The Sizes Of Candidate Z~9-10 Galaxies : Confirmation Of The Bright Candels Sample And Relation With Luminosity And Mass., Benne W. Holwerda, R. J. Bouwens, P. A. Oesch, R. Smit, G. D. Illingworth, I. Labbe
Faculty and Staff Scholarship
Recently, a small sample of six z ∼ 9–10 candidates was discovered in CANDELS that are ~-´ 10 20 more luminous than any of the previous z ∼ 9–10 galaxies identified over the HUDF/XDF and CLASH fields. We measure the sizes of these candidates to map out the size evolution of galaxies from the earliest observable times. Their sizes are also used to provide a valuable constraint on whether these unusual galaxy candidates are at high redshift. Using galfit to derive sizes from the CANDELS F160W images of these candidates, we find a mean size of 0. 13 0. 0 …
The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Stellar Masses, Sizes, And Radial Profiles For 2352 Nearby Galaxies., Juan Carlos Muñoz-Mateos, Kartik Sheth, Michael Regan, Taehyun Kim, Jarkko Laine, Santiago Erroz-Ferrer, Armando Gil De Paz, Sebastien Comeron, Joannah Hinz, Eija Laurikainen, Heikki Salo, E. Athanassoula, Albert Bosma, Alexandre Y. Bouquin, Eva Schinnerer, Luis C. Ho, Johan H. Knapen, Sharon Meidt, Miguel Querejeta, Trisha Mizusawa, Mark Seibert, Seppo Laine, Helene M. Courtois
The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Stellar Masses, Sizes, And Radial Profiles For 2352 Nearby Galaxies., Juan Carlos Muñoz-Mateos, Kartik Sheth, Michael Regan, Taehyun Kim, Jarkko Laine, Santiago Erroz-Ferrer, Armando Gil De Paz, Sebastien Comeron, Joannah Hinz, Eija Laurikainen, Heikki Salo, E. Athanassoula, Albert Bosma, Alexandre Y. Bouquin, Eva Schinnerer, Luis C. Ho, Johan H. Knapen, Sharon Meidt, Miguel Querejeta, Trisha Mizusawa, Mark Seibert, Seppo Laine, Helene M. Courtois
Faculty and Staff Scholarship
The Spitzer Survey of Stellar Structure in Galaxies is a volume, magnitude, and size-limited survey of 2352 nearby galaxies with deep imaging at 3.6 and 4.5 μm. In this paper, we describe our surface photometry pipeline and showcase the associated data products that we have released to the community. We also identify the physical mechanisms leading to different levels of central stellar mass concentration for galaxies with the same total stellar mass. Finally, we derive the local stellar mass–size relation at 3.6 μm for galaxies of different morphologies. Our radial profiles reach stellar mass surface densities below ~1 pc M …
The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Precise Stellar Mass Distributions From Automated Dust Correction At 3.6 Μm., Miguel Querejeta, Sharon Meidt, Eva Schinnerer, Mauricio Cisternas, Juan Carlos Muñoz-Mateos, Kartik Sheth, Johan H. Knapen, Glenn Van De Ven, Mark A. Norris, Reynier Peletier, Eija Laurikainen, Heikki Salo, Benne W. Holwerda, E. Athanassoula, Albert Bosma, Brent Groves, Luis C. Ho, Dimitri A. Gadotti, Dennis Zaritsky, Michael Regan, Joannah Hinz, Armando Gil De Paz, Karin Menendez-Delmestre, Mark Seibert, Trisha Mizusawa, Taehyun Kim, Santiago Erroz-Ferrer, Jarkko Laine, Sebastien Comeron
The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Precise Stellar Mass Distributions From Automated Dust Correction At 3.6 Μm., Miguel Querejeta, Sharon Meidt, Eva Schinnerer, Mauricio Cisternas, Juan Carlos Muñoz-Mateos, Kartik Sheth, Johan H. Knapen, Glenn Van De Ven, Mark A. Norris, Reynier Peletier, Eija Laurikainen, Heikki Salo, Benne W. Holwerda, E. Athanassoula, Albert Bosma, Brent Groves, Luis C. Ho, Dimitri A. Gadotti, Dennis Zaritsky, Michael Regan, Joannah Hinz, Armando Gil De Paz, Karin Menendez-Delmestre, Mark Seibert, Trisha Mizusawa, Taehyun Kim, Santiago Erroz-Ferrer, Jarkko Laine, Sebastien Comeron
Faculty and Staff Scholarship
The mid-infrared is an optimal window to trace stellar mass in nearby galaxies and the 3.6 mm IRAC band has been exploited to this effect, but such mass estimates can be biased by dust emission. We present our pipeline to reveal the old stellar flux at 3.6 μm and obtain stellar mass maps for more than 1600 galaxies available from the Spitzer Survey of Stellar Structure in Galaxies (S4 G). This survey consists of images in two infrared bands (3.6 and 4.5 mm ), and we use the Independent Component Analysis (ICA) method presented in Meidt et al. to separate …
Uv Luminosity Functions At Redshifts Z~4 To Z~10 : 10,000 Galaxies From Hst Legacy Fields., R. J. Bouwens, G. D. Illingworth, P. A. Oesch, M. Trenti, I. Labbe, L. Bradley, C. M. Carollo, P. G. Van Dokkum, V. Gonzalez, Benne W. Holwerda, M. Franx, L. Spitler, R. Smit, D. Magee
Uv Luminosity Functions At Redshifts Z~4 To Z~10 : 10,000 Galaxies From Hst Legacy Fields., R. J. Bouwens, G. D. Illingworth, P. A. Oesch, M. Trenti, I. Labbe, L. Bradley, C. M. Carollo, P. G. Van Dokkum, V. Gonzalez, Benne W. Holwerda, M. Franx, L. Spitler, R. Smit, D. Magee
Faculty and Staff Scholarship
The remarkable Hubble Space Telescope (HST) data sets from the CANDELS, HUDF09, HUDF12, ERS, and BoRG/HIPPIES programs have allowed us to map the evolution of the rest-frame UV luminosity function (LF) from z ~ 10 to z ~ 4. We develop new color criteria that more optimally utilize the full wavelength coverage from the optical, near-IR, and mid-IR observations over our search fields, while simultaneously minimizing the incompleteness and eliminating redshift gaps. We have identified 5859, 3001, 857, 481, 217, and 6 galaxy candidates at z ~ 4, z ~ 5, z ~ 6, z ~ 7, z ~ 8, …
Weighing Galaxy Disks With The Baryonic Tully-Fisher Relation, Stacy S. Mcgaugh
Weighing Galaxy Disks With The Baryonic Tully-Fisher Relation, Stacy S. Mcgaugh
Faculty Scholarship
We estimate the stellar masses of disk galaxies with two independent methods: a photometrically self-consistent color?mass-to-light ratio relation (CMLR) from population synthesis models, and the baryonic Tully?Fisher relation (BTFR) calibrated by gas-rich galaxies. These two methods give consistent results. The CMLR correctly converts distinct Tully?Fisher relations in different bands into the same BTFR. The BTFR is consistent with Mb ∝ Vf4 over nearly six decades in mass, with no hint of a change in slope over that range. The intrinsic scatter in the BTFR is negligible, implying that the IMF of disk galaxies is effectively universal. The gas-rich BTFR suggests …
High-Precision Photometric Redshifts From Spitzer/Irac : Extreme [3.6] - [4.5] Colors Identify Galaxies In The Redshift Range Z ~ 6.6 - 6.9., Renske Smit, Rychard J. Bouwens, Marijn Franx, Pascal A. Oesch, Matthew L. N. Ashby, S. P. Millner, Ivo Labbe, Benne W. Holwerda, Giovanni G. Fazio, J. S. Huang
High-Precision Photometric Redshifts From Spitzer/Irac : Extreme [3.6] - [4.5] Colors Identify Galaxies In The Redshift Range Z ~ 6.6 - 6.9., Renske Smit, Rychard J. Bouwens, Marijn Franx, Pascal A. Oesch, Matthew L. N. Ashby, S. P. Millner, Ivo Labbe, Benne W. Holwerda, Giovanni G. Fazio, J. S. Huang
Faculty and Staff Scholarship
One of the most challenging aspects of studying galaxies in the z 7 universe is the infrequent confirmation of their redshifts through spectroscopy, a phenomenon thought to occur from the increasing opacity of the intergalactic medium to Lyα photons at z > 6.5. The resulting redshift uncertainties inhibit the efficient search for [C II] in z ~ 7 galaxies with sub-millimeter instruments such as ALMA, given their limited scan speed for faint lines. One means by which to improve the precision of the inferred redshifts is to exploit the potential impact of strong nebular emission lines on the colors of …
Globular Cluster Populations : First Results From S4g Early-Type Galaxies., Dennis Zaritsky, Manuel Aravena, E. Athanassoula, Albert Bosma, Sebastien Comeron, Bruce G. Elmegreen, Santiago Erroz-Ferrer, Dimitri A. Gadotti, Joannah Hinz, Luis C. Ho, Benne W. Holwerda, Johan H. Knapen, Jarkko Laine, Eija Laurikainen, Juan Carlos Munoz-Mateos, Heikki Salo, Kartik Sheth
Globular Cluster Populations : First Results From S4g Early-Type Galaxies., Dennis Zaritsky, Manuel Aravena, E. Athanassoula, Albert Bosma, Sebastien Comeron, Bruce G. Elmegreen, Santiago Erroz-Ferrer, Dimitri A. Gadotti, Joannah Hinz, Luis C. Ho, Benne W. Holwerda, Johan H. Knapen, Jarkko Laine, Eija Laurikainen, Juan Carlos Munoz-Mateos, Heikki Salo, Kartik Sheth
Faculty and Staff Scholarship
Using 3.6μm images of 97 early-type galaxies, we develop and verify methodology to measure globular cluster populations from the S4G survey images. We find that (1) the ratio, TN, of the number of clusters, NCL, to parent galaxy stellar mass, M∗, rises weakly with M∗ for early-type galaxies with M∗ > 1010 M when we calculate galaxy masses using a universal stellar initial mass function (IMF) but that the dependence of TN on M∗ is removed entirely once we correct for the recently uncovered systematic variation of IMF with M∗; and (2) for M∗ < 1010 M, there is no trend between NCL and M∗, the scatter in TN is significantly larger (approaching two orders of magnitude), and there is evidence to support a previous, independent suggestion of two families of galaxies. The behavior of NCL in the lower-mass systems is more difficult to measure because these systems are inherently cluster-poor, but our results may add to previous evidence that large variations in cluster formation and destruction efficiencies are to be found among low-mass galaxies. The average fraction of stellar mass in clusters is ∼0.0014 for M∗ > 1010 M and can be as large …
The Mass Profile And Shape Of Bars In The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Search For An Age Indicator For Bars., Taehyun Kim, Kartik Sheth, Dimitri A. Gadotti, Myung Gyoon Lee, Dennis Zaritsky, Bruce G. Elmegreen, E. Athanassoula, Albert Bosma, Benne W. Holwerda, Luis C. Ho, Sebastien Comeron, Johan H. Knapen, Joannah Hinz, Juan Carlos Munoz-Mateos, Santiago Erroz-Ferrer, Ronald J. Buta, Minjin Kim, Eija Laurikainen, Heikki Salo, Barry F. Madore, Jarkko Laine, Karin Menendez-Delmestre, Michael Regan, Bonita De Swardt, Armando Gil De Paz, Mark Seibert, Trisha Mizusawa
The Mass Profile And Shape Of Bars In The Spitzer Survey Of Stellar Structure In Galaxies (S4g) : Search For An Age Indicator For Bars., Taehyun Kim, Kartik Sheth, Dimitri A. Gadotti, Myung Gyoon Lee, Dennis Zaritsky, Bruce G. Elmegreen, E. Athanassoula, Albert Bosma, Benne W. Holwerda, Luis C. Ho, Sebastien Comeron, Johan H. Knapen, Joannah Hinz, Juan Carlos Munoz-Mateos, Santiago Erroz-Ferrer, Ronald J. Buta, Minjin Kim, Eija Laurikainen, Heikki Salo, Barry F. Madore, Jarkko Laine, Karin Menendez-Delmestre, Michael Regan, Bonita De Swardt, Armando Gil De Paz, Mark Seibert, Trisha Mizusawa
Faculty and Staff Scholarship
We have measured the radial light profiles and global shapes of bars using two-dimensional 3.6μm image decompositions for 144 face-on barred galaxies from the Spitzer Survey of Stellar Structure in Galaxies. The bar surface brightness profile is correlated with the stellar mass and bulge-to-total (B/T) ratio of their host galaxies. Bars in massive and bulge-dominated galaxies (B/T > 0.2) show a flat profile, while bars in less massive, disk-dominated galaxies (B/T ∼ 0) show an exponential, disk-like profile with a wider spread in the radial profile than in the bulge-dominated galaxies. The global two-dimensional shapes of bars, however, are rectangular/boxy, independent …
Spectroscopic Confirmation Of The Existence Of Large, Diffuse Galaxies In The Coma Cluster, Pieter Van Dokkum, Aaron Romanowsky, Roberto Abraham, Jean Brodie, Charlie Conroy, Marla Geha, Allison Merritt, Alexa Villaume, Jielai Zhang
Spectroscopic Confirmation Of The Existence Of Large, Diffuse Galaxies In The Coma Cluster, Pieter Van Dokkum, Aaron Romanowsky, Roberto Abraham, Jean Brodie, Charlie Conroy, Marla Geha, Allison Merritt, Alexa Villaume, Jielai Zhang
Faculty Publications
No abstract provided.
Galaxy And Mass Assembly (Gama) : Galaxy Close Pairs, Mergers And The Future Fate Of Stellar Mass., A. S. G. Robotham, S. P. Driver, L. J. M. Davies, A. M. Hopkins, I. K. Baldry, N. K. Agius, A. E. Bauer, J. Bland-Hawthorn, S. Brough, M. J. I. Brown, M. Cluver, R. De Propis, M. J. Drinkwater, Benne W. Holwerda, L. S. Kelvin, M. A. Lara-Lopez, J. Liske, Angel R. Lopez-Sanchez, J. Loveday, S. Mahajan, T. Mcnaught-Roberts, A. Moffett, P. Norberg, D. Obreschkow, M. S. Owers, S. J. Penny, K. A. Pimbblet, M. Prescott, E. N. Taylor, E. Van Kampen, S. M. Wilkins
Galaxy And Mass Assembly (Gama) : Galaxy Close Pairs, Mergers And The Future Fate Of Stellar Mass., A. S. G. Robotham, S. P. Driver, L. J. M. Davies, A. M. Hopkins, I. K. Baldry, N. K. Agius, A. E. Bauer, J. Bland-Hawthorn, S. Brough, M. J. I. Brown, M. Cluver, R. De Propis, M. J. Drinkwater, Benne W. Holwerda, L. S. Kelvin, M. A. Lara-Lopez, J. Liske, Angel R. Lopez-Sanchez, J. Loveday, S. Mahajan, T. Mcnaught-Roberts, A. Moffett, P. Norberg, D. Obreschkow, M. S. Owers, S. J. Penny, K. A. Pimbblet, M. Prescott, E. N. Taylor, E. Van Kampen, S. M. Wilkins
Faculty and Staff Scholarship
We use a highly complete subset of the Galaxy And Mass Assembly II (GAMA-II) redshift sample to fully describe the stellar mass dependence of close pairs and mergers between 108 and 1012 M⊙. Using the analytic form of this fit we investigate the total stellar mass accreting on to more massive galaxies across all mass ratios. Depending on how conservatively we select our robust merging systems, the fraction of mass merging on to more massive companions is 2.0–5.6 per cent. Using the GAMA-II data we see no significant evidence for a change in the close pair fraction between redshift z …
Evidence For The Concurrent Growth Of Thick Discs And Central Mass Concentrations From S4g Imaging., S. Comeron, B. G. Elmegreen, H. Salo, E. Laurikainen, Benne W. Holwerda, J. H. Knapen
Evidence For The Concurrent Growth Of Thick Discs And Central Mass Concentrations From S4g Imaging., S. Comeron, B. G. Elmegreen, H. Salo, E. Laurikainen, Benne W. Holwerda, J. H. Knapen
Faculty and Staff Scholarship
We have produced 3.6 μm + 4.5 μm vertically integrated radial luminosity profiles of 69 edge-on galaxies from the Spitzer Survey of Stellar Structure in Galaxies (S4G). We decomposed the luminosity profiles into a disc and a central mass concentration (CMC). These fits, combined with thin/thick disc decompositions from our previous studies, allow us to estimate the masses of the CMCs, the thick discs, and the thin discs (ℳCMC, ℳT, and ℳT). We obtained atomic disc masses (ℳg) from the literature. We then consider the CMC and the thick disc to be dynamically hot components and the thin …
Color-Mass-To-Light-Ratio Relations For Disk Galaxies, Stacy S. Mcgaugh
Color-Mass-To-Light-Ratio Relations For Disk Galaxies, Stacy S. Mcgaugh
Faculty Scholarship
We combine Spitzer 3.6 μm observations of a sample of disk galaxies spanning over 10 mag in luminosity with optical luminosities and colors to test population synthesis prescriptions for computing stellar mass. Many commonly employed models fail to provide self-consistent results: the stellar mass estimated from the luminosity in one band can differ grossly from that of another band for the same galaxy. Independent models agree closely in the optical (V band), but diverge at longer wavelengths. This effect is particularly pronounced in recent models with substantial contributions from TP-AGB stars. We provide revised color-mass-to-light ratio relations that yield self-consistent …
Morphology And Environment Of Galaxies With Disc Breaks In The S4g And Nirs0s, J. Laine, E. Laurikainen, H. Salo, S. Comeron, R. J. Buta, D. Zaritsky, E. Athanassoula, A. Bosma, J.-C. Munoz-Mateos, D. A. Gadotti, J. L. Hinz, S. Erroz-Ferrer, A. Gil De Paz, T. Kim, K. Menendez-Delmestre, T. Mizusawa, M. W. Regan, M. Seibert, K. Sheth
Morphology And Environment Of Galaxies With Disc Breaks In The S4g And Nirs0s, J. Laine, E. Laurikainen, H. Salo, S. Comeron, R. J. Buta, D. Zaritsky, E. Athanassoula, A. Bosma, J.-C. Munoz-Mateos, D. A. Gadotti, J. L. Hinz, S. Erroz-Ferrer, A. Gil De Paz, T. Kim, K. Menendez-Delmestre, T. Mizusawa, M. W. Regan, M. Seibert, K. Sheth
Aerospace, Physics, and Space Science Faculty Publications
We study the surface brightness profiles of disc galaxies in the 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies (S4G) and Ks-band images from the Near-Infrared S0-Sa galaxy Survey (NIRS0S). We particularly connect properties of single exponential (type I), downbending double exponential (type II), and upbending double exponential (type III) disc profile types, to structural components of galaxies by using detailed morphological classifications, and size measurements of rings and lenses. We also study how the local environment of the galaxies affects the profile types by calculating parameters describing the environmental density and the tidal …
The Baryonic Tully-Fisher Relationship For S4g Galaxies And The "Condensed" Baryon Fraction Of Galaxies., Dennis Zaritsky, Helene M. Courtois, Juan Carlos Munoz-Mateos, Jenny Sorce, S. Erroz-Ferrer, S. Comeron, D. A. Gadotti, A. Gil De Paz, J. L. Hinz, E. Laurikainen, T. Kim, J. Laine, K. Menendez-Delmestre, T. Mizusawa, M. W. Regan, H. Salo, M. Seibert, K. Sheth, E. Athanassoula, A. Bosma, M. Cisternas, Luis C. Ho, Benne W. Holwerda
The Baryonic Tully-Fisher Relationship For S4g Galaxies And The "Condensed" Baryon Fraction Of Galaxies., Dennis Zaritsky, Helene M. Courtois, Juan Carlos Munoz-Mateos, Jenny Sorce, S. Erroz-Ferrer, S. Comeron, D. A. Gadotti, A. Gil De Paz, J. L. Hinz, E. Laurikainen, T. Kim, J. Laine, K. Menendez-Delmestre, T. Mizusawa, M. W. Regan, H. Salo, M. Seibert, K. Sheth, E. Athanassoula, A. Bosma, M. Cisternas, Luis C. Ho, Benne W. Holwerda
Faculty and Staff Scholarship
We combine data from the Spitzer Survey for Stellar Structure in Galaxies, a recently calibrated empirical stellar mass estimator from Eskew et al., and an extensive database of H i spectral line profiles to examine the baryonic Tully–Fisher (BTF) relation. We find (1) that the BTF has lower scatter than the classic Tully–Fisher (TF) relation and is better described as a linear relationship, confirming similar previous results, (2) that the inclusion of a radial scale in the BTF decreases the scatter but only modestly, as seen previously for the TF relation, and (3) that the slope of the BTF, which …
The Luminosity Function At Z ~ 8 From 97 Y-Band Dropouts : Inferences About Reionization., Kasper B. Schmidt, Tommaso Treu, Michele Trenti, Larry D. Bradley, Brandon C. Kelly, Pascal A. Oesch, Benne W. Holwerda, J. Michael Shull, Massimo Stiavelli
The Luminosity Function At Z ~ 8 From 97 Y-Band Dropouts : Inferences About Reionization., Kasper B. Schmidt, Tommaso Treu, Michele Trenti, Larry D. Bradley, Brandon C. Kelly, Pascal A. Oesch, Benne W. Holwerda, J. Michael Shull, Massimo Stiavelli
Faculty and Staff Scholarship
We present the largest search to date for Y-band dropout galaxies (z ∼ 8 Lyman break galaxies, LBGs) based on 350 arcmin2 of Hubble Space Telescope observations in the V, Y, J, and H bands from the Brightest of Reionizing Galaxies (BoRG) survey. In addition to previously published data, the BoRG13 data set presented here includes approximately 50 arcmin2 of new data and deeper observations of two previous BoRG pointings, from which we present 9 new z ∼ 8 LBG candidates, bringing the total number of BoRG Y-band dropouts to 38 with 25.5 mJ 27.6 (AB system). We introduce a …
Unveiling The Structure Of Barred Galaxies At 3.6 Μm With The Spitzer Survey Of Stellar Structure In Galaxies (S4g). I. Disk Breaks., Taehyun Kim, Dimitri A. Gadotti, Kartik Sheth, E. Athanassoula, Albert Bosma, Myung Gyoon Lee, Barry F. Madore, Bruce G. Elmegreen, Johan H. Knapen, Dennis Zaritsky, Luis C. Ho, Sebastien Comeron, Benne W. Holwerda, Joannah L. Hinz, Juan Carlos Munoz-Mateos, Mauricio Cisternas, Santiago Erroz-Ferrer, Ron Buta, Eija Laurikainen, Heikki Salo, Jarkko Laine, Karin Menendez-Delmestre, Michael W. Regan, Bonita De Swardt, Armando Gil De Paz, Mark Seibert, Trisha Mizusawa
Unveiling The Structure Of Barred Galaxies At 3.6 Μm With The Spitzer Survey Of Stellar Structure In Galaxies (S4g). I. Disk Breaks., Taehyun Kim, Dimitri A. Gadotti, Kartik Sheth, E. Athanassoula, Albert Bosma, Myung Gyoon Lee, Barry F. Madore, Bruce G. Elmegreen, Johan H. Knapen, Dennis Zaritsky, Luis C. Ho, Sebastien Comeron, Benne W. Holwerda, Joannah L. Hinz, Juan Carlos Munoz-Mateos, Mauricio Cisternas, Santiago Erroz-Ferrer, Ron Buta, Eija Laurikainen, Heikki Salo, Jarkko Laine, Karin Menendez-Delmestre, Michael W. Regan, Bonita De Swardt, Armando Gil De Paz, Mark Seibert, Trisha Mizusawa
Faculty and Staff Scholarship
We have performed two-dimensional multicomponent decomposition of 144 local barred spiral galaxies using 3.6 μm images from the Spitzer Survey of Stellar Structure in Galaxies. Our model fit includes up to four components (bulge, disk, bar, and a point source) and, most importantly, takes into account disk breaks. We find that ignoring the disk break and using a single disk scale length in the model fit for Type II (down-bending) disk galaxies can lead to differences of 40% in the disk scale length, 10% in bulge-to-total luminosity ratio (B/T), and 25% in bar-to-total luminosity ratios. We find that for galaxies …
Interpreting The Ionization Sequence In Agn Emission-Line Spectra, Chris T. Richardson, James T. Allen, Jack A. Baldwin, Paul C. Hewett, Gary J. Ferland
Interpreting The Ionization Sequence In Agn Emission-Line Spectra, Chris T. Richardson, James T. Allen, Jack A. Baldwin, Paul C. Hewett, Gary J. Ferland
Physics and Astronomy Faculty Publications
We investigate the physical cause of the great range in the ionization level seen in the spectra of narrow-lined active galactic nuclei (AGN). We used a recently developed technique called mean field independent component analysis to identify examples of individual Sloan Digital Sky Survey galaxies whose spectra are not dominated by emission due to star formation (SF), which we therefore designate as AGN. We assembled high signal-to-noise ratio (S/N) composite spectra of a sequence of these AGN defined by the ionization level of their narrow-line regions (NLR), and extending down to very low ionization cases. We then used a local …
X-Ray Nuclear Activity In S4g Barred Galaxies : No Link Between Bar Strength And Co-Occurrent Supermassive Black Hole Fueling., Mauricio Cisternas, Dimitri A. Gadotti, Johan H. Knapen, Taehyun Kim, Simon Diaz-Garcia, Eija Laurikainen, Heikki Salo, Omaira Gonzalez-Martin, Luis C. Ho, Bruce G. Elmegreen, Dennis Zaritsky, Kartik Sheth, E. Athanassoula, Albert Bosma, Sebastien Comeron, Santiago Erroz-Ferrer, Armando Gil De Paz, Joannah L. Hinz, Benne W. Holwerda, Jarkko Laine, Sharon Meidt, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Michael W. Regan, Mark Seibert
X-Ray Nuclear Activity In S4g Barred Galaxies : No Link Between Bar Strength And Co-Occurrent Supermassive Black Hole Fueling., Mauricio Cisternas, Dimitri A. Gadotti, Johan H. Knapen, Taehyun Kim, Simon Diaz-Garcia, Eija Laurikainen, Heikki Salo, Omaira Gonzalez-Martin, Luis C. Ho, Bruce G. Elmegreen, Dennis Zaritsky, Kartik Sheth, E. Athanassoula, Albert Bosma, Sebastien Comeron, Santiago Erroz-Ferrer, Armando Gil De Paz, Joannah L. Hinz, Benne W. Holwerda, Jarkko Laine, Sharon Meidt, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Michael W. Regan, Mark Seibert
Faculty and Staff Scholarship
Stellar bars can lead to gas inflow toward the center of a galaxy and stimulate nuclear star formation. However, there is no compelling evidence on whether they also feed a central supermassive black hole: by measuring the fractions of barred active and inactive galaxies, previous studies have yielded conflicting results. In this paper, we aim to understand the lack of observational evidence for bar-driven active galactic nucleus (AGN) activity by studying a sample of 41 nearby (d < 35 Mpc) barred galaxies from the Spitzer Survey for Stellar Structure in Galaxies. We use Chandra observations to measure nuclear 2–10 keV X-ray luminosities and estimate Eddington ratios, together with Spitzer 3.6 μm imaging to quantify the strength of the stellar bar in two independent ways: (1) from its structure, as traced by its ellipticity and boxiness, and (2) from its gravitational torque Qb, taken as the maximum ratio of the tangential force to the mean background radial force. In this way, rather than discretizing the presence of both stellar bars and nuclear activity, we are able to account for the continuum of bar strengths and degrees of AGN activity. We find nuclear X-ray sources in 31 out of 41 galaxies with median X-ray luminosity and Eddington ratio of LX = 4.3×1038 erg s−1 and Lbol/LEdd = 6.9×10−6, respectively, consistent with low-luminosity AGN activity. Including upper limits for those galaxies without nuclear detections, we find no significant correlation between any of the bar strength indicators and the degree of nuclear activity, irrespective of galaxy luminosity, stellar mass, Hubble type, or bulge size. Strong bars do not favor brighter or more efficient nuclear activity, implying that at least for the low-luminosity regime, supermassive black hole fueling is not closely connected to large-scale features.
The Redshift And Mass Dependence On The Formation Of The Hubble Sequence At Z > 1 From Candels/Uds, Alice Mortlock, Christopher J. Conselice, William G. Hartley, Jamie R. Ownsworth, Caterina Lani, Asa F. L. Bluck, Omar Almaini, Kenneth Duncan, Arjen Van Der Wel, Anton M. Koekemoer, Avishai Dekel, Romeel Davé, Harry C. Ferguson, Duilia F. De Mello, Jeffrey A. Newman, Sandra M. Faber, Norman A. Grogin, Dalibor D. Kocevski, Kamson Lai
The Redshift And Mass Dependence On The Formation Of The Hubble Sequence At Z > 1 From Candels/Uds, Alice Mortlock, Christopher J. Conselice, William G. Hartley, Jamie R. Ownsworth, Caterina Lani, Asa F. L. Bluck, Omar Almaini, Kenneth Duncan, Arjen Van Der Wel, Anton M. Koekemoer, Avishai Dekel, Romeel Davé, Harry C. Ferguson, Duilia F. De Mello, Jeffrey A. Newman, Sandra M. Faber, Norman A. Grogin, Dalibor D. Kocevski, Kamson Lai
Physics and Astronomy Faculty Publications
In this paper we present a detailed study of the structures and morphologies of a sample of 1188 massive galaxies with M* ≥ 1010 M⊙between redshifts z = 1 and 3 within the Ultra Deep Survey (UDS) region of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) field. Using this sample we determine how galaxy structure and morphology evolve with time, and investigate the nature of galaxy structure at high redshift. We visually classify our sample into discs, ellipticals and peculiar systems and correct for redshift effects on these classifications through simulations. We find significant …
Stellar Populations And The Star Formation Histories Of Low Surface Brightness Galaxies. Ii. H Ii Regions, Stacy S. Mcgaugh
Stellar Populations And The Star Formation Histories Of Low Surface Brightness Galaxies. Ii. H Ii Regions, Stacy S. Mcgaugh
Faculty Scholarship
The luminosities, colors, and Ha emission for 429 H II regions in 54 low surface brightness (LSB) galaxies are presented. While the number of H II regions per galaxy is lower in LSB galaxies compared to star-forming irregulars and spirals, there is no indication that the size or luminosity function of H II regions differs from other galaxy types. The lower number of Hii regions per galaxy is consistent with their lower total star formation rates. The fraction of the total LH α contributed by H II regions varies from 10% to 90% in LSB galaxies (the rest of the …
The Impact Of Bars On Disk Breaks As Probed By S4g Imaging., Juan Carlos Munoz-Mateos, Kartik Sheth, Armando Gil De Paz, Sharon Meidt, E. Athanassoula, Albert Bosma, Sebastien Comeron, Debra M. Elmegreen, Bruce G. Elmegreen, Santiago Erroz-Ferrer, Dimitri A. Gadotti, Joannah L. Hinz, Luis C. Ho, Benne W. Holwerda, Thomas H. Jarrett, Taehyun Kim, Johan H. Knapen, Jarkko Laine, Eija Laurikainen, Barry F. Madore, Karin Menendez-Delmestre, Trisha Mizusawa, Michael Regan, Heikki Salo, Eva Schinnerer, Mark Seibert, Ramin Skibba, Dennis Zaritsky
The Impact Of Bars On Disk Breaks As Probed By S4g Imaging., Juan Carlos Munoz-Mateos, Kartik Sheth, Armando Gil De Paz, Sharon Meidt, E. Athanassoula, Albert Bosma, Sebastien Comeron, Debra M. Elmegreen, Bruce G. Elmegreen, Santiago Erroz-Ferrer, Dimitri A. Gadotti, Joannah L. Hinz, Luis C. Ho, Benne W. Holwerda, Thomas H. Jarrett, Taehyun Kim, Johan H. Knapen, Jarkko Laine, Eija Laurikainen, Barry F. Madore, Karin Menendez-Delmestre, Trisha Mizusawa, Michael Regan, Heikki Salo, Eva Schinnerer, Mark Seibert, Ramin Skibba, Dennis Zaritsky
Faculty and Staff Scholarship
We have analyzed the radial distribution of old stars in a sample of 218 nearby face-on disks, using deep 3.6μm images from the Spitzer Survey of Stellar Structure in Galaxies. In particular, we have studied the structural properties of those disks with a broken or down-bending profile. We find that, on average, disks with a genuine single-exponential profile have a scale length and a central surface brightness which are intermediate to those of the inner and outer components of a down-bending disk with the same total stellar mass. In the particular case of barred galaxies, the ratio between the break …
Emission-Line Galaxies From The Hubble Space Telescope Probing Evolution And Reionization Spectroscopically (Pears) Grism Survey. Ii. The Complete Sample., N. Pirzkal, Barry Rothberg, Chun Ly, Sangeeta Malhotra, James E. Rhoads, Norman A. Grogin, Tomas Dahlen, Kai G. Noeske, Gerhardt R. Meurer, Jeremy R. Walsh, Nimish P. Hathi, Seth H. Cohen, Andrea Bellini, Benne W. Holwerda, Amber N. Straughn, Matthew Mechtley, Rogier A. Windhorst
Emission-Line Galaxies From The Hubble Space Telescope Probing Evolution And Reionization Spectroscopically (Pears) Grism Survey. Ii. The Complete Sample., N. Pirzkal, Barry Rothberg, Chun Ly, Sangeeta Malhotra, James E. Rhoads, Norman A. Grogin, Tomas Dahlen, Kai G. Noeske, Gerhardt R. Meurer, Jeremy R. Walsh, Nimish P. Hathi, Seth H. Cohen, Andrea Bellini, Benne W. Holwerda, Amber N. Straughn, Matthew Mechtley, Rogier A. Windhorst
Faculty and Staff Scholarship
We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on board Hubble Space Telescope. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations complemented by the spectroscopic results. Using the PEARS data, we are able to identify star-forming galaxies (SFGs) within the redshift volume 0 < z < 1.5. Star-forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allows us to detect the presence of multiple emission-line regions (ELRs) within a single galaxy. We identified a total of 1162 Hα, [O iii], and/or [O ii] emission lines in the PEARS sample of 906 galaxies to a limiting flux of ∼10−18 erg s−1 cm−2. The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis, we find three key results: (1) the computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; (2) the star-forming systems show evidence of complex morphologies with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass. (3) Also, the number density of SFGs with M∗ 109 M decreases by an order of magnitude at z 0.5 relative to the number at 0.5 < z < 0.9, supporting the argument of galaxy downsizing.
Classification And Analysis Of Emission-Line Galaxies Using Mean Field Independent Component Analysis, James T. Allen, Paul C. Hewett, Chris T. Richardson, Gary J. Ferland, Jack A. Baldwin
Classification And Analysis Of Emission-Line Galaxies Using Mean Field Independent Component Analysis, James T. Allen, Paul C. Hewett, Chris T. Richardson, Gary J. Ferland, Jack A. Baldwin
Physics and Astronomy Faculty Publications
We present an analysis of the optical spectra of narrow emission-line galaxies, based on mean field independent component analysis (MFICA), a blind source separation technique. Samples of galaxies were drawn from the Sloan Digital Sky Survey (SDSS) and used to generate compact sets of ‘continuum’ and ‘emission-line’ component spectra. These components can be linearly combined to reconstruct the observed spectra of a wider sample of galaxies. Only 10 components – five continuum and five emission line – are required to produce accurate reconstructions of essentially all narrow emission-line galaxies to a very high degree of accuracy; the median absolute deviations …
The Brightest Of Reionizing Galaxies Survey : Constraints On The Bright End Of The Z ~ 8 Luminosity Function., L. D. Bradley, M. Trenti, P. A. Oesch, M. Stiavelli, T. Treu, R. J. Bouwens, J. M. Shull, Benne W. Holwerda, N. Pirzkal
The Brightest Of Reionizing Galaxies Survey : Constraints On The Bright End Of The Z ~ 8 Luminosity Function., L. D. Bradley, M. Trenti, P. A. Oesch, M. Stiavelli, T. Treu, R. J. Bouwens, J. M. Shull, Benne W. Holwerda, N. Pirzkal
Faculty and Staff Scholarship
We report the discovery of 33 Lyman-break galaxy candidates at z ∼ 8 detected in Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging as part of the Brightest of Reionizing Galaxies (BoRG) pure-parallel survey. The ongoing BoRG survey currently has the largest area (274 arcmin2) with Y098 (or Y105), J125, and H160 band coverage needed to search for z ∼ 8 galaxies, about three times the current CANDELS area, and slightly larger than what will be the final CANDELS wide component with Y105 data (required to select z ∼ 8 sources). Our sample of 33 relatively bright Y098-dropout galaxies …
Evolution In The Dust Lane Fraction Of Edge-On L*V Spiral Galaxies Since Z = 0.8., Benne W. Holwerda, J. J. Dalcanton, D. Radburn-Smith, R. S. De Jong, P. Guhathakurta, A. Koekemoer, R. J. Allen, T. Boker
Evolution In The Dust Lane Fraction Of Edge-On L*V Spiral Galaxies Since Z = 0.8., Benne W. Holwerda, J. J. Dalcanton, D. Radburn-Smith, R. S. De Jong, P. Guhathakurta, A. Koekemoer, R. J. Allen, T. Boker
Faculty and Staff Scholarship
The presence of a well-defined and narrow dust lane in an edge-on spiral galaxy is the observational signature of a thin and dense molecular disk, in which gravitational collapse has overcome turbulence. Using a sample of galaxies out to z ∼ 1 extracted from the COSMOS survey, we identify the fraction of massive (L∗ V ) disks that display a dust lane. Our goal is to explore the evolution in the stability of the molecular interstellar medium (ISM) disks in spiral galaxies over a cosmic timescale. We check the reliability of our morphological classifications against changes in rest-frame wavelength, resolution, …
Outer-Disk Populations In Ngc 7793 : Evidence For Stellar Radial Migration., David J. Radburn-Smith, Rok Roskar, Victor P. Debattista, Julianne J. Dalcanton, David Streich, Roelof S. De Jong, Marija Vlajic, Benne W. Holwerda, Chris W. Purcell, Andrew E. Dolphin, Daniel B. Zucker
Outer-Disk Populations In Ngc 7793 : Evidence For Stellar Radial Migration., David J. Radburn-Smith, Rok Roskar, Victor P. Debattista, Julianne J. Dalcanton, David Streich, Roelof S. De Jong, Marija Vlajic, Benne W. Holwerda, Chris W. Purcell, Andrew E. Dolphin, Daniel B. Zucker
Faculty and Staff Scholarship
We analyzed the radial surface brightness profile of the spiral galaxy NGC 7793 using HST/ACS images from the GHOSTS survey and a new HST/WFC3 image across the disk break. We used the photometry of resolved stars to select distinct populations covering a wide range of stellar ages. We found breaks in the radial profiles of all stellar populations at 280 (∼5.1 kpc). Beyond this disk break, the profiles become steeper for younger populations. This same trend is seen in numerical simulations where the outer disk is formed almost entirely by radial migration. We also found that the older stars of …
The Source Counts Of Submillimetre Galaxies Detected At Λ= 1.1 Mm, K. S. Scott, G. W. Wilson, I. Aretxaga, J. E. Austermann, E. L. Chapin, J. S. Dunlop, H. Ezawa, M. Halpern, B. Hatsukade, D. H. Hughes, R. Kawabe, S. Kim, K. Kohno, James D. Lowenthal, A. Montaña, K. Nakanishi, T. Oshima, D. Sanders, D. Scott, N. Scoville, Y. Tamura, D. Welch, M. S. Yun, M. Zeballos
The Source Counts Of Submillimetre Galaxies Detected At Λ= 1.1 Mm, K. S. Scott, G. W. Wilson, I. Aretxaga, J. E. Austermann, E. L. Chapin, J. S. Dunlop, H. Ezawa, M. Halpern, B. Hatsukade, D. H. Hughes, R. Kawabe, S. Kim, K. Kohno, James D. Lowenthal, A. Montaña, K. Nakanishi, T. Oshima, D. Sanders, D. Scott, N. Scoville, Y. Tamura, D. Welch, M. S. Yun, M. Zeballos
Astronomy: Faculty Publications
The source counts of galaxies discovered at submillimetre and millimetre wavelengths provide important information on the evolution of infrared-bright galaxies. We combine the data from six blank-field surveys carried out at 1.1mm with AzTEC, totalling 1.6deg in area with root-mean-square depths ranging from 0.4 to 1.7mJy, and derive the strongest constraints to date on the 1.1 mm source counts at flux densities S = 1-12mJy. Using additional data from the AzTEC Cluster Environment Survey to extend the counts to S ∼ 20mJy, we see tentative evidence for an enhancement relative to the exponential drop in the counts at S ∼ …
Hubble Space Telescope Imaging Of Post-Starburst Quasars, S. Cales, M. Brotherton, Zhaohui Shang, Vardha Bennert, Gabriela Canalizo, R. Stoll, R. Ganguly, D. Berk, Cassandra Paul, A. Diamond-Stanic
Hubble Space Telescope Imaging Of Post-Starburst Quasars, S. Cales, M. Brotherton, Zhaohui Shang, Vardha Bennert, Gabriela Canalizo, R. Stoll, R. Ganguly, D. Berk, Cassandra Paul, A. Diamond-Stanic
Faculty Publications
We present images of 29 post-starburst quasars (PSQs) from a Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) Wide Field Channel Snapshot program. These broadlined active galactic nuclei (AGNs) possess the spectral signatures of massive (Mburst ∼ 1010 M⊙), moderate-aged stellar populations (hundreds of Myr). Thus, their composite nature provides insight into the AGN–starburst connection. We measure quasar-to-host galaxy light contributions via semi-automated two-dimensional light profile fits of point-spread-function-subtracted images. We examine the host morphologies and model the separate bulge and disk components. The HST/ACS-F606W images reveal an equal number of spiral (13/29) and early-type (13/29) hosts, with the …
A Search For Young Stars In The S0 Galaxies Of A Super-Group At Z=0.37, Dennis W. Just, Dennis Zaritsky, Kim-Vy H. Tran, Anthony H. Gonzalez, Stefan Kautsch, John Moustakas
A Search For Young Stars In The S0 Galaxies Of A Super-Group At Z=0.37, Dennis W. Just, Dennis Zaritsky, Kim-Vy H. Tran, Anthony H. Gonzalez, Stefan Kautsch, John Moustakas
Chemistry and Physics Faculty Articles
We analyze Galaxy Evolution Explorer UV data for a system of four gravitationally bound groups at z = 0.37, SG1120, which is destined to merge into a Coma-mass cluster by z = 0, to study how galaxy properties may change during cluster assembly. Of the 38 visually classified S0 galaxies, with masses ranging from log (M *)[M ☉] ≈ 10-11, we detect only one in the near-UV (NUV) channel, a strongly star-forming S0 that is the brightest UV source with a measured redshift placing it in SG1120. Stacking the undetected S0 galaxies (which generally lie on or near …
On The Clustering Of Sub-Millimeter Galaxies, Christina Williams, Mauro Giavalisco, Cristiano Porciani, Min Yun, Alexandra Pope, Kimberly Scott, Jason Austermann, Itziar Aretxaga, Bunyo Hatsukade, Kyoung-Soo Lee, Grant Wilson, J. Ryan Cybulski, David Hughes, Ryo Kawabe, Kotaro Kohno, Thushara Perera, F. Peter Schloerb
On The Clustering Of Sub-Millimeter Galaxies, Christina Williams, Mauro Giavalisco, Cristiano Porciani, Min Yun, Alexandra Pope, Kimberly Scott, Jason Austermann, Itziar Aretxaga, Bunyo Hatsukade, Kyoung-Soo Lee, Grant Wilson, J. Ryan Cybulski, David Hughes, Ryo Kawabe, Kotaro Kohno, Thushara Perera, F. Peter Schloerb
Scholarship
We measure the angular two-point correlation function of sub-millimeter galaxies (SMGs) from 1.1-millimeter imaging of the COSMOS field with the AzTEC camera and ASTE 10-meter telescope. These data yields one of the largest contiguous samples of SMGs to date, covering an area of 0.72 degrees^2 down to a 1.26 mJy/beam (1-sigma) limit, including 189 (328) sources with S/N greater than 3.5 (3). We can only set upper limits to the correlation length r_0, modeling the correlation function as a power-law with pre-assigned slope. Assuming existing redshift distributions, we derive 68.3% confidence level upper limits of r_0 < 6-8 h^-1 Mpc at 3.7 mJy, and r_0 < 11-12 h^-1 Mpc at 4.2 mJy. Although consistent with most previous estimates, these upper limits imply that the real r_0 is likely smaller. This casts doubts on the robustness of claims that SMGs are characterized by significantly stronger spatial clustering, (and thus larger mass), than differently selected galaxies at high-redshift. Using Monte Carlo simulations we show that even strongly clustered distributions of galaxies can appear unclustered when sampled with limited sensitivity and coarse angular resolution common to current sub-millimeter surveys. The simulations, however, also show that unclustered distributions can appear strongly clustered under these circumstances. From the simulations, we predict that at our survey depth, a mapped area of two degrees^2 is needed to reconstruct the correlation function, assuming smaller beam sizes of future surveys (e.g. the Large Millimeter Telescope's 6" beam size). At present, robust measures of the clustering strength of bright SMGs appear to be below the reach of most observations.