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Galaxies: formation

University of Louisville

Articles 1 - 17 of 17

Full-Text Articles in Astrophysics and Astronomy

The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology, Lori E. Porter, Benne Holwerda, Sandor Kruk, Maritza Lara-López, Kevin A. Pimbblet, Christopher P A Henry, Sarah Casura, Lee S. Kelvin Jul 2023

The Loneliest Galaxies In The Universe: A Gama And Galaxy Zoo Study On Void Galaxy Morphology, Lori E. Porter, Benne Holwerda, Sandor Kruk, Maritza Lara-López, Kevin A. Pimbblet, Christopher P A Henry, Sarah Casura, Lee S. Kelvin

Faculty Scholarship

The large-scale structure of the Universe is comprised of galaxy filaments, tendrils, and voids. The majority of the Universe’s volume is taken up by these voids, which exist as underdense, but not empty, regions. The galaxies found inside these voids are expected to be some of the most isolated objects in the Universe. This study, using the Galaxy and Mass Assembly (GAMA) and Galaxy Zoo surveys, aims to investigate basic physical properties and morphology of void galaxies versus field (filament and tendril) galaxies. We use void galaxies with stellar masses (⁠M∗" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; …


The Bright End Of The Z~9 And Z~10 Uv Luminosity Functions Using All Five Candels Fields., R. J. Bouwens, P. A. Oesch, I. Labbe, G. D. Illingworth, G. G. Fazio, D. Coe, Benne W. Holwerda, R. Smit, M. Stefanon, P. G. Van Dokkum, M. Trenti, M. L. N. Ashby, J. S. Huang, L. Spitler, C. Straatman, L. Bradley, D. Magee Oct 2016

The Bright End Of The Z~9 And Z~10 Uv Luminosity Functions Using All Five Candels Fields., R. J. Bouwens, P. A. Oesch, I. Labbe, G. D. Illingworth, G. G. Fazio, D. Coe, Benne W. Holwerda, R. Smit, M. Stefanon, P. G. Van Dokkum, M. Trenti, M. L. N. Ashby, J. S. Huang, L. Spitler, C. Straatman, L. Bradley, D. Magee

Faculty Scholarship

The deep, wide-area (∼800–900 arcmin2 ) near-infrared/WFC3/IR + Spitzer/IRAC observations over the CANDELS fields have been a remarkable resource for constraining the bright end of high-redshift UV luminosity functions. However, the lack of Hubble Space Telescope (HST) 1.05 μm observations over the CANDELS fields has made it difficult to identify z ∼ 9–10 sources robustly, since such data are needed to confirm the presence of an abrupt Lyman break at 1.2 μm. Here, we report on the successful identification of many such z ∼ 9–10 sources from a new HST program (z9-CANDELS) that targets the highest-probability z ∼ 9–10 galaxy …


Galaxy And Mass Assembly (Gama) : M–Re Relations Of Z = 0 Bulges, Discs And Spheroids., Rebecca Lange, Amanda J. Moffett, Simon P. Driver, Aaron S. G. Robotham, Claudia Del P. Lagos, Lee S. Kelvin, Christopher Conselice, Berta Margalef-Bentabol, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Malcolm Bremer, Sarah Brough, Michelle Cluver, Matthew Colless, Luke J. M. Davies, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Jochen Liske, Steven Phillipps, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Eelco Van Kampen, Angus H. Wright Oct 2016

Galaxy And Mass Assembly (Gama) : M–Re Relations Of Z = 0 Bulges, Discs And Spheroids., Rebecca Lange, Amanda J. Moffett, Simon P. Driver, Aaron S. G. Robotham, Claudia Del P. Lagos, Lee S. Kelvin, Christopher Conselice, Berta Margalef-Bentabol, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Malcolm Bremer, Sarah Brough, Michelle Cluver, Matthew Colless, Luke J. M. Davies, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Jochen Liske, Steven Phillipps, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Eelco Van Kampen, Angus H. Wright

Faculty Scholarship

We perform automated bulge + disc decomposition on a sample of ∼7500 galaxies from the Galaxy And Mass Assembly (GAMA) survey in the redshift range of 0.002 < z < 0.06 using Structural Investigation of Galaxies via Model Analysis, a wrapper around GALFIT3. To achieve robust profile measurements, we use a novel approach of repeatedly fitting the galaxies, varying the input parameters to sample a large fraction of the input parameter space. Using this method, we reduce the catastrophic failure rate significantly and verify the confidence in the fit independently of χ2. Additionally, using the median of the final fitting values and the 16th and 84th percentile produces more realistic error estimates than those provided by GALFIT, which are known to be underestimated. We use the results of our decompositions to analyse the stellar mass – half-light radius relations of bulges, discs and spheroids. We further investigate the association of components with a parent disc or elliptical relation to provide definite z = 0 disc and spheroid M–Re relations. We conclude by comparing our local disc and spheroid M–Re to simulated data from EAGLE and high-redshift data from Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Ultra Deep Survey. We show the potential of using the M–Re relation to study galaxy evolution in both cases but caution that for a fair comparison, all data sets need to be processed and analysed in the same manner.


Galaxy And Mass Assembly (Gama) : Galaxy Colour Gradients Versus Colour, Structure, And Luminosity., Rebecca Kennedy, Steven P. Bamford, Boris Haußler, Sarah Brough, Benne W. Holwerda, Andrew M. Hopkins, Marina Vika, Benedetta Vulcani Sep 2016

Galaxy And Mass Assembly (Gama) : Galaxy Colour Gradients Versus Colour, Structure, And Luminosity., Rebecca Kennedy, Steven P. Bamford, Boris Haußler, Sarah Brough, Benne W. Holwerda, Andrew M. Hopkins, Marina Vika, Benedetta Vulcani

Faculty Scholarship

Using single-component fits to SDSS/UKIDSS images of galaxies in the G09 region of the GAMA survey we study radial colour gradients across the galaxy population. We use the multi-wavelength information provided by MegaMorph analysis of galaxy light profiles to calculate intrinsic colour gradients, and divide into six subsamples split by overall Sérsic index (n) and galaxy colour. We find a bimodality in the colour gradients of high- and low-n galaxies in all wavebands which varies with overall galaxy luminosity. Global trends in colour gradients therefore result from combining the contrasting behaviour of a number of different galaxy populations. The ubiquity …


Galaxy And Mass Assembly (Gama) : Understanding The Wavelength Dependence Of Galaxy Structure With Bulge-Disc Decompositions., Rebecca Kennedy, Steven P. Bamford, Boris Haußler, Ivan K. Baldry, Malcolm Bremer, Sarah Brough, Michael J. I. Brown, Simon P. Driver, Kenneth Duncan, Alister W. Graham, Benne W. Holwerda, Andrew M. Hopkins, Lee S. Kelvin, Rebecca Lange, Steven Phillipps, Marina Vika, Benedetta Vulcani Aug 2016

Galaxy And Mass Assembly (Gama) : Understanding The Wavelength Dependence Of Galaxy Structure With Bulge-Disc Decompositions., Rebecca Kennedy, Steven P. Bamford, Boris Haußler, Ivan K. Baldry, Malcolm Bremer, Sarah Brough, Michael J. I. Brown, Simon P. Driver, Kenneth Duncan, Alister W. Graham, Benne W. Holwerda, Andrew M. Hopkins, Lee S. Kelvin, Rebecca Lange, Steven Phillipps, Marina Vika, Benedetta Vulcani

Faculty Scholarship

With a large sample of bright, low-redshift galaxies with optical–near-IR imaging from the GAMA survey we use bulge-disc decompositions to understand the wavelength-dependent behaviour of single-Sérsic structural measurements. We denote the variation in single-Sérsic index with wavelength as N N , likewise for effective radius we use R R . We find that most galaxies with a substantial disc, even those with no discernable bulge, display a high value of N N . The increase in Sérsic index to longer wavelengths is therefore intrinsic to discs, apparently resulting from radial variations in stellar population and/or dust reddening. Similarly, low values …


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 Nov 2015

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 Jul 2015

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 Mar 2015

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 Feb 2015

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 Jan 2015

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 …


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 Jun 2014

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 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 May 2014

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 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 Feb 2014

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 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 …


Constraining The Age Of The Ngc 4565 Hi Disk Warp : Determining The Origin Of Gas Warps., David J. Radburn-Smith, Roelof S. De Jong, David Streich, Eric F. Bell, Julianne J. Dalcanton, Andrew E. Dolphin, Adrienne M. Stilp, Antonela Monachesi, Benne W. Holwerda, Jeremy Bailin Jan 2014

Constraining The Age Of The Ngc 4565 Hi Disk Warp : Determining The Origin Of Gas Warps., David J. Radburn-Smith, Roelof S. De Jong, David Streich, Eric F. Bell, Julianne J. Dalcanton, Andrew E. Dolphin, Adrienne M. Stilp, Antonela Monachesi, Benne W. Holwerda, Jeremy Bailin

Faculty Scholarship

We have mapped the distribution of young and old stars in the gaseous H i warp of NGC 4565. We find a clear correlation of young stars (< 600 Myr) with the warp but no coincident old stars (> 1 Gyr), which places an upper limit on the age of the structure. The formation rate of the young stars, which increased ∼ 300 Myr ago relative to the surrounding regions, is (6.3+2.5 −1.5) × 10−5 M yr−1 kpc−2. This implies a ∼ 60 ± 20 Gyr depletion time of the H i warp, similar to the timescales calculated for the outer H i disks of nearby spiral galaxies. While some stars …


A Unified Picture Of Breaks And Truncations In Spiral Galaxies From Sdss And S4g Imaging., Ignacio Martin-Navarro, Judit Bakos, Ignacio Trujillo, Johan H. Knapen, E. Athanassoula, A. Bosma, Sebastien Comeron, Bruce G. Elmegreen, Santiago Erroz-Ferrer, Dimitri A. Gadotti, Armando Gil De Paz, Joannah L. Hinz, Luis C. Ho, Benne W. Holwerda, Taehyun Kim, Jarkko Laine, Eija Laurikainen, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Michael W. Regan, Heikki Salo, Mark Seibert, Kartik Sheth Dec 2012

A Unified Picture Of Breaks And Truncations In Spiral Galaxies From Sdss And S4g Imaging., Ignacio Martin-Navarro, Judit Bakos, Ignacio Trujillo, Johan H. Knapen, E. Athanassoula, A. Bosma, Sebastien Comeron, Bruce G. Elmegreen, Santiago Erroz-Ferrer, Dimitri A. Gadotti, Armando Gil De Paz, Joannah L. Hinz, Luis C. Ho, Benne W. Holwerda, Taehyun Kim, Jarkko Laine, Eija Laurikainen, Karin Menendez-Delmestre, Trisha Mizusawa, Juan Carlos Munoz-Mateos, Michael W. Regan, Heikki Salo, Mark Seibert, Kartik Sheth

Faculty Scholarship

The mechanism causing breaks in the radial surface-brightness distribution of spiral galaxies is not yet well known. Despite theoretical efforts, there is not a unique explanation for these features and the observational results are not conclusive. In an attempt to address this problem, we have selected a sample of 34 highly inclined spiral galaxies present in both the Sloan Digital Sky Survey (SDSS) and the Spitzer Survey of Stellar Structure in Galaxies (S4G). We have measured the surface-brightness profiles in the five Sloan optical bands and in the 3.6-µm Spitzer band. We have also calculated the colour and stellar surface …


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 Dec 2012

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 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 …


The Ghosts Survey. I. Hubble Space Telescope Advanced Camera For Surveys Data., D. J. Radburn-Smith, R. S. De Jong, A. C. Seth, J. Bailin, E. F. Bell, T. M. Brown, J. S. Bullock, S. Courteau, J. J. Dalcanton, H. C. Ferguson, P. Goudfrooij, S. Holfeltz, Benne W. Holwerda, C. Purcell, J. Sick, D. Streich, M. Vlajic, D. B. Zucker Aug 2011

The Ghosts Survey. I. Hubble Space Telescope Advanced Camera For Surveys Data., D. J. Radburn-Smith, R. S. De Jong, A. C. Seth, J. Bailin, E. F. Bell, T. M. Brown, J. S. Bullock, S. Courteau, J. J. Dalcanton, H. C. Ferguson, P. Goudfrooij, S. Holfeltz, Benne W. Holwerda, C. Purcell, J. Sick, D. Streich, M. Vlajic, D. B. Zucker

Faculty Scholarship

We present an overview of the GHOSTS survey, the largest study to date of the resolved stellar populations in the outskirts of disk galaxies. The sample consists of 14 disk galaxies within 17 Mpc, whose outer disks and halos are imaged with the Hubble Space Telescope Advanced Camera for Surveys (ACS). In the first paper of this series, we describe the sample, explore the benefits of using resolved stellar populations, and discuss our ACS F606W and F814W photometry. We use artificial star tests to assess completeness and use overlapping regions to estimate photometric uncertainties. The median depth of the survey …