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Full-Text Articles in Astrophysics and Astronomy
Galaxy And Mass Assembly (Gama) : The Wavelength Dependence Of Galaxy Structure Versus Redshift And Luminosity., Rebecca Kennedy, Steven P. Bamford, Ivan K. Baldry, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Lee S. Kelvin, Rebecca Lange, Amanda J. Moffett, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Marina Vika, Benedetta Vulcani
Galaxy And Mass Assembly (Gama) : The Wavelength Dependence Of Galaxy Structure Versus Redshift And Luminosity., Rebecca Kennedy, Steven P. Bamford, Ivan K. Baldry, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Lee S. Kelvin, Rebecca Lange, Amanda J. Moffett, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Marina Vika, Benedetta Vulcani
Faculty Scholarship
We study how the sizes and radial profiles of galaxies vary with wavelength, by fitting Sersic ´ functions simultaneously to imaging in nine optical and near-infrared bands. To quantify the wavelength dependence of effective radius we use the ratio, R, of measurements in two rest-frame bands. The dependence of Sersic index on wavelength, ´ N , is computed correspondingly. Vulcani et al. have demonstrated that different galaxy populations present sharply contrasting behaviour in terms of R and N . Here we study the luminosity dependence of this result. We find that at higher luminosities, early-type galaxies display a more substantial …
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 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 …
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 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 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 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 …