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Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Astrophysics and Astronomy

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2012

University of Massachusetts Amherst

Articles 1 - 18 of 18

Full-Text Articles in Physical Sciences and Mathematics

The Assembly Of Galaxies Over Cosmic Time, Yicheng Guo Sep 2012

The Assembly Of Galaxies Over Cosmic Time, Yicheng Guo

Open Access Dissertations

To Understand how galaxies were assembled across the cosmic time remains one of the most outstanding questions in astronomy. The core of this question is how today's Hubble Sequence, namely the differentiation of galaxy morphology and its correlation to galaxy physical properties, is formed. In this thesis, we investigate the origin of the Hubble Sequence through galaxies at z~2, an epoch when the cosmic star formation activity reaches its peak and the properties of galaxies undergo dramatic transitions. Galaxies at z~2 have two important features that are distinct from nearby galaxies: much higher frequency of clumpy morphology in star-forming systems, …

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D1 Dopamine Receptor Signaling Is Modulated By The R7 Rgs Protein Eat-16 And The R7 Binding Protein Rsbp-1 In Caenoerhabditis Elegans Motor Neurons, K. A. Wani, M. Catanese, R. Normantowicz, M Herd, K. N. Maher, Daniel Chase May 2012

D1 Dopamine Receptor Signaling Is Modulated By The R7 Rgs Protein Eat-16 And The R7 Binding Protein Rsbp-1 In Caenoerhabditis Elegans Motor Neurons, K. A. Wani, M. Catanese, R. Normantowicz, M Herd, K. N. Maher, Daniel Chase

Daniel Chase

Dopamine signaling modulates voluntary movement and reward-driven behaviors by acting through G protein-coupled receptors in striatal neurons, and defects in dopamine signaling underlie Parkinson's disease and drug addiction. Despite the importance of understanding how dopamine modifies the activity of striatal neurons to control basal ganglia output, the molecular mechanisms that control dopamine signaling remain largely unclear. Dopamine signaling also controls locomotion behavior in Caenorhabditis elegans. To better understand how dopamine acts in the brain we performed a large-scale dsRNA interference screen in C. elegans for genes required for endogenous dopamine signaling and identified six genes (eat-16, rsbp-1, unc-43, flp-1, grk-1, …

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The Atacama Cosmology Telescope: Data Characterization And Map Making, Rolando Dünner, Matthew Hasselfield, Tobias A. Marriage, Jon Sievers, Viviana Acquaviva, Graeme E. Addison, Peter A. R. Ade, Paula Aguirre, Mandana Amiri, John William Appel, L. Felipe Barrientos, Elia S. Battistelli, J. Richard Bond, Ben Brown, Bryce Burger, Erminia Calabrese, Jay Chervenak, Sudeep Das, Mark J. Devlin, Simon R. Dicker, W. Bertrand Doriese, Joanna Dunkley, Thomas Essinger-Hileman, Ryan P. Fisher, Megan B. Gralla, Joseph W. Fowler, Amir Hajian, Mark Halpern, Carlos Hernández-Monteagudo, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Renée Hlozek, Kevin M. Huffenberger, David H. Hughes, John P. Hughes, Leopoldo Infante, Kent D. Irwin, Jean Baptiste Juin, Madhuri Kaul, Jeff Klein, Arthur Kosowsky, Judy M. Lau, Michele Limon, Yen-Ting Lin, Thibaut Louis, Robert H. Lupton, Danica Marsden, Krista Martocci, Phil Mauskopf, Felipe Menanteau, Kavilan Moodley, Harvey Moseley, Calvin B. Betterfield, Michael D. Niemack, Michael R. Nolta, Lyman A. Page, Lucas Parker, Bruce Partridge, Hernan Quintana, Beth Reid, Neelima Sehgal, Blake D. Sherwin, David N. Spergel, Suzanne T. Staggs, Daniel S. Swetz, Eric R. Switzer, Robert Thornton, Hy Trac, Carole Tucker, Ryan Warne, Grant Wilson, Ed Wollack, Yue Zhao Jan 2012

The Atacama Cosmology Telescope: Data Characterization And Map Making, Rolando Dünner, Matthew Hasselfield, Tobias A. Marriage, Jon Sievers, Viviana Acquaviva, Graeme E. Addison, Peter A. R. Ade, Paula Aguirre, Mandana Amiri, John William Appel, L. Felipe Barrientos, Elia S. Battistelli, J. Richard Bond, Ben Brown, Bryce Burger, Erminia Calabrese, Jay Chervenak, Sudeep Das, Mark J. Devlin, Simon R. Dicker, W. Bertrand Doriese, Joanna Dunkley, Thomas Essinger-Hileman, Ryan P. Fisher, Megan B. Gralla, Joseph W. Fowler, Amir Hajian, Mark Halpern, Carlos Hernández-Monteagudo, Gene C. Hilton, Matt Hilton, Adam D. Hincks, Renée Hlozek, Kevin M. Huffenberger, David H. Hughes, John P. Hughes, Leopoldo Infante, Kent D. Irwin, Jean Baptiste Juin, Madhuri Kaul, Jeff Klein, Arthur Kosowsky, Judy M. Lau, Michele Limon, Yen-Ting Lin, Thibaut Louis, Robert H. Lupton, Danica Marsden, Krista Martocci, Phil Mauskopf, Felipe Menanteau, Kavilan Moodley, Harvey Moseley, Calvin B. Betterfield, Michael D. Niemack, Michael R. Nolta, Lyman A. Page, Lucas Parker, Bruce Partridge, Hernan Quintana, Beth Reid, Neelima Sehgal, Blake D. Sherwin, David N. Spergel, Suzanne T. Staggs, Daniel S. Swetz, Eric R. Switzer, Robert Thornton, Hy Trac, Carole Tucker, Ryan Warne, Grant Wilson, Ed Wollack, Yue Zhao

Grant Wilson

We present a description of the data reduction and mapmaking pipeline used for the 2008 observing season of the Atacama Cosmology Telescope (ACT). The data presented here at 148 GHz represent 12% of the 90 TB collected by ACT from 2007 to 2010. In 2008 we observed for 136 days, producing a total of 1423 hours of data (11 TB for the 148 GHz band only), with a daily average of 10.5 hours of observation. From these, 1085 hours were devoted to a 850 deg^2 stripe (11.2 hours by 9.1 deg) centered on a declination of -52.7 deg, while 175 …

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Resolving The Far-Ir Line Deficit: Photoelectric Heating And Far-Ir Line Cooling In Ngc 1097 And Ngc 4559, Kevin V. Croxall, J. D. Smith, M. G. Wolfire, H. Roussel, K. M. Sandstrom, B. T. Draine, G. Aniano, D. A. Dale, L. Armus, P. Beirão, G. Helou, A. D. Bolatto, P. N. Appleton, B. R. Brandl, Daniela Calzetti, A. F. Crocker, M. Galametz, B. A. Groves, C.-N. Hao, L. K. Hunt, B. D. Johnson, R, C, Kennicutt, J. Koda, O. Krause, Y. Li, S. E. Meidt, E. J. Murphy, N. Rahman, H.-W. Rix, M. Sauvage, E. Schinnerer, F. Walter, C. D. Wilson Jan 2012

Resolving The Far-Ir Line Deficit: Photoelectric Heating And Far-Ir Line Cooling In Ngc 1097 And Ngc 4559, Kevin V. Croxall, J. D. Smith, M. G. Wolfire, H. Roussel, K. M. Sandstrom, B. T. Draine, G. Aniano, D. A. Dale, L. Armus, P. Beirão, G. Helou, A. D. Bolatto, P. N. Appleton, B. R. Brandl, Daniela Calzetti, A. F. Crocker, M. Galametz, B. A. Groves, C.-N. Hao, L. K. Hunt, B. D. Johnson, R, C, Kennicutt, J. Koda, O. Krause, Y. Li, S. E. Meidt, E. J. Murphy, N. Rahman, H.-W. Rix, M. Sauvage, E. Schinnerer, F. Walter, C. D. Wilson

Daniela Calzetti

The physical state of interstellar gas and dust is dependent on the processes which heat and cool this medium. To probe heating and cooling of the ISM over a large range of infrared surface brightness, on sub-kiloparsec scales, we employ line maps of [C \ii] 158 $\mu$m, [O \one] 63 $\mu$m, and [N \ii] 122 $\mu$m in NGC 1097 and NGC 4559, obtained with the PACS spectrometer onboard {\it Herschel}. We matched new observations to existing Spitzer-IRS data that trace the total emission of polycyclic aromatic hydrocarbons (PAHs). We confirm at small scales in these galaxies that the canonical measure …

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Cool And Warm Dust Emission From M33 (Herm33es), E. M. Xilouris, F. S. Tabatabaei, M. Boquien, C. Kramer, C. Buchbender, F. Bertoldi, S. Anderl, J. Braine, S. Verley, M. Relaño, G. Quintana-Lacaci, S. Akras, R. Beck, Daniela Calzetti, F. Combes, M. Gonzalez, P. Gratier, C. Henkel, F. Israel, B. Koribalski, S. Lord, B. Mookerjea, E. Rosolowsky, G. Stacey, R. P. J. Tilanus, F. Van Der Tak, P. Van Der Werf Jan 2012

Cool And Warm Dust Emission From M33 (Herm33es), E. M. Xilouris, F. S. Tabatabaei, M. Boquien, C. Kramer, C. Buchbender, F. Bertoldi, S. Anderl, J. Braine, S. Verley, M. Relaño, G. Quintana-Lacaci, S. Akras, R. Beck, Daniela Calzetti, F. Combes, M. Gonzalez, P. Gratier, C. Henkel, F. Israel, B. Koribalski, S. Lord, B. Mookerjea, E. Rosolowsky, G. Stacey, R. P. J. Tilanus, F. Van Der Tak, P. Van Der Werf

Daniela Calzetti

We study the far-infrared emission from the nearby spiral galaxy M33 in order to investigate the dust physical properties such as the temperature and the luminosity density across the galaxy. Taking advantage of the unique wavelength coverage (100, 160, 250, 350 and 500 micron) of the Herschel Space Observatory and complementing our dataset with Spitzer-IRAC 5.8 and 8 micron and Spitzer-MIPS 24 and 70 micron data, we construct temperature and luminosity density maps by fitting two modified blackbodies of a fixed emissivity index of 1.5. We find that the 'cool' dust grains are heated at temperatures between 11 and 28 …

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Dust And Gas Power-Spectrum In M33 (Herm33es), F. Combes, M. Boquien, C. Kramer, E. M. Xilouris, F. Bertoldi, J. Braine, C. Buchbender, Daniela Calzetti, P. Gratier, F. Israel, B. Koribalski, S. Lord, G. Quintana-Lacaci, M. Relaño, M. Röllig, G. Stacey, F. S. Tabatabaei, R. P. J. Tilanus, F. Van Der Tak, P. Van Der Werf, S. Verley Jan 2012

Dust And Gas Power-Spectrum In M33 (Herm33es), F. Combes, M. Boquien, C. Kramer, E. M. Xilouris, F. Bertoldi, J. Braine, C. Buchbender, Daniela Calzetti, P. Gratier, F. Israel, B. Koribalski, S. Lord, G. Quintana-Lacaci, M. Relaño, M. Röllig, G. Stacey, F. S. Tabatabaei, R. P. J. Tilanus, F. Van Der Tak, P. Van Der Werf, S. Verley

Daniela Calzetti

Power spectra of de-projected images of late-type galaxies in gas and/or dust emission are very useful diagnostics of the dynamics and stability of their interstellar medium. Previous studies have shown that the power spectra can be approximated as two power-laws, a shallow one at large scales (larger than 500 pc) and a steeper one at small scales, with the break between the two corresponding to the line-of-sight thickness of the galaxy disk. We present a thorough analysis of the power spectra of the dust and gas emission at several wavelengths in the nearby galaxy M33. In particular, we use the …

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Evidence For Significant Growth In The Stellar Mass Of Brightest Cluster Galaxies Over The Past 10 Billion Years, C. Lidman, J. Suherli, A. Muzzin, Grant Wilson, R. Demarco, S. Brough, A. Rettura, J. Cox, A. Degroot, H. K. C. Yee, D. Gilbank, H. Hoekstra, M. Balogh, E. Ellingson, A. Hicks, J. Nantais, A. Noble, M. Lacy, J. Surace Jan 2012

Evidence For Significant Growth In The Stellar Mass Of Brightest Cluster Galaxies Over The Past 10 Billion Years, C. Lidman, J. Suherli, A. Muzzin, Grant Wilson, R. Demarco, S. Brough, A. Rettura, J. Cox, A. Degroot, H. K. C. Yee, D. Gilbank, H. Hoekstra, M. Balogh, E. Ellingson, A. Hicks, J. Nantais, A. Noble, M. Lacy, J. Surace

Grant Wilson

Using new and published data, we construct a sample of 160 brightest cluster galaxies (BCGs) spanning the redshift interval 0.03 < z < 1.63. We use this sample, which covers 70% of the history of the universe, to measure the growth in the stellar mass of BCGs after correcting for the correlation between the stellar mass of the BCG and the mass of the cluster in which it lives. We find that the stellar mass of BCGs increase by a factor of 1.8 between z=0.9 and z=0.2. Compared to earlier works, our result is closer to the predictions of semi-analytic models. However, BCGs at z=0.9, relative to BCGs at z=0.2, are still a factor of 1.5 more massive than the predictions of these models. Star formation rates in BCGs at z~1 are generally to low to result in significant amounts of mass. Instead, it is likely that most of the mass build up occurs through mainly dry mergers in which perhaps half of the mass is lost to the intra-cluster medium of the cluster.

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A Remarkably Simple And Accurate Method For Computing The Bayes Factor From A Markov Chain Monte Carlo Simulation Of The Posterior Distribution In High Dimension, Martin D. Weinberg, Ilsang Yoon, Neal S. Katz Jan 2012

A Remarkably Simple And Accurate Method For Computing The Bayes Factor From A Markov Chain Monte Carlo Simulation Of The Posterior Distribution In High Dimension, Martin D. Weinberg, Ilsang Yoon, Neal S. Katz

Neal S. Katz

Weinberg (2012) described a constructive algorithm for computing the marginal likelihood, Z, from a Markov chain simulation of the posterior distribution. Its key point is: the choice of an integration subdomain that eliminates subvolumes with poor sampling owing to low tail-values of posterior probability. Conversely, this same idea may be used to choose the subdomain that optimizes the accuracy of Z. Here, we explore using the simulated distribution to define a small region of high posterior probability, followed by a numerical integration of the sample in the selected region using the volume tessellation algorithm described inWeinberg (2012). Even more promising …

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A Study Of Heating And Cooling Of The Ism In Ngc 1097 With Herschel-Pacs And Spitzer-Irs, P. Beirão, L. Armus, G. Helou, P. N. Appleton, J.-D. T. Smith, K. V. Croxall, E. J. Murphy, D. A. Dale, B. T. Draine, M. G. Wolfire, K. M. Sandstrom, G. Aniano, A. D. Bolatto, B. Groves, B. R. Brandl, E. Schinnerer, A. F. Crocker, J. L. Hinz, H.-W. Rix, R. C. Kennicutt, Daniela Calzetti, A. Gil De Paz, G. Dumas, M. Galametz, K. D. Gordon, C.-N. Hao, B. Johnson, J. Koda, O. Krause, T. Van Der Laan, A. K. Leroy, Y. Li, S. E. Meidt, J. D. Meyer, N. Rahman, H. Roussel, M. Sauvage, S. Srinivasan, L. Vigroux, F. Walter, B. E. Warren Jan 2012

A Study Of Heating And Cooling Of The Ism In Ngc 1097 With Herschel-Pacs And Spitzer-Irs, P. Beirão, L. Armus, G. Helou, P. N. Appleton, J.-D. T. Smith, K. V. Croxall, E. J. Murphy, D. A. Dale, B. T. Draine, M. G. Wolfire, K. M. Sandstrom, G. Aniano, A. D. Bolatto, B. Groves, B. R. Brandl, E. Schinnerer, A. F. Crocker, J. L. Hinz, H.-W. Rix, R. C. Kennicutt, Daniela Calzetti, A. Gil De Paz, G. Dumas, M. Galametz, K. D. Gordon, C.-N. Hao, B. Johnson, J. Koda, O. Krause, T. Van Der Laan, A. K. Leroy, Y. Li, S. E. Meidt, J. D. Meyer, N. Rahman, H. Roussel, M. Sauvage, S. Srinivasan, L. Vigroux, F. Walter, B. E. Warren

Daniela Calzetti

NGC 1097 is a nearby Seyfert 1 galaxy with a bright circumnuclear starburst ring, a strong large-scale bar and an active nucleus. We present a detailed study of the spatial variation of the far infrared (FIR) [CII]158um and [OI]63um lines and mid-infrared H2 emission lines as tracers of gas cooling, and of the polycyclic aromatic hydrocarbon (PAH) bands as tracers of the photoelectric heating, using Herschel-PACS, and Spitzer-IRS infrared spectral maps. We focus on the nucleus and the ring, and two star forming regions (Enuc N and Enuc S). We estimated a photoelectric gas heating efficiency ([CII]158um+[OI]63um)/PAH in the ring …

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The Spitzer Extragalactic Representative Volume Survey (Servs): Survey Definition And Goals, J.-C. Mauduit, M. Lacy, D. Farrah, J. A. Surace, M. Jarvis, S. Oliver, C. Maraston, M. Vaccari, L. Marchetti, G. Zeimann, E. A. Gonzáles-Solares, J. Pforr, A. O. Petric, B. Henriques, P. A. Thomas, J. Afonso, A. Rettura, Grant Wilson, J. T. Falder, J. E. Geach, M. Huynh, R. P. Norrish, N. Seymour, G. T. Richards, S. A. Stanford, D. M. Alexander, R. H. Becker, P. N. Best, L. Bizzocchi, D. Bonfield, N. Castro, A. Cava, S. Chapman, N. Christopher, D. L. Clements, G. Covone, N. Dubois, J. S. Dunlop, E. Dyke, A. Edge, H. C. Ferguson, S. Foucaud, A. Franceschini, R. R. Gal, J. K. Grant, M. Grossi, E. Hatziminaoglou, S. Hickey, J. A. Hodge, J.-S. Huang, R. J. Ivison, M. Kim, O. Lefevre, M. Lehnert, C. J. Lonsdale, L. M. Lubin, R. J. Mclure, H. Messias, A. Martínez-Sansigre, A. M. J. Mortier, D. M. Nielsen, M. Ouchi, G. Parish, I. Perez-Fournon, M. Pierre, S. Rawlings, A. Readhead, S. E. Ridgway, D. Rigopoulou, A. K. Romer, I. G. Roseboom, H. J. A. Rottgering, M. Rowan-Robinson, A. Sajina, C. J. Simpson, I. Smail, G. K. Squires, J. A. Stevens, R. Taylor, M. Trichas, T. Urrutia, E. Van Kampen, A. Verma, C. K. Xu Jan 2012

The Spitzer Extragalactic Representative Volume Survey (Servs): Survey Definition And Goals, J.-C. Mauduit, M. Lacy, D. Farrah, J. A. Surace, M. Jarvis, S. Oliver, C. Maraston, M. Vaccari, L. Marchetti, G. Zeimann, E. A. Gonzáles-Solares, J. Pforr, A. O. Petric, B. Henriques, P. A. Thomas, J. Afonso, A. Rettura, Grant Wilson, J. T. Falder, J. E. Geach, M. Huynh, R. P. Norrish, N. Seymour, G. T. Richards, S. A. Stanford, D. M. Alexander, R. H. Becker, P. N. Best, L. Bizzocchi, D. Bonfield, N. Castro, A. Cava, S. Chapman, N. Christopher, D. L. Clements, G. Covone, N. Dubois, J. S. Dunlop, E. Dyke, A. Edge, H. C. Ferguson, S. Foucaud, A. Franceschini, R. R. Gal, J. K. Grant, M. Grossi, E. Hatziminaoglou, S. Hickey, J. A. Hodge, J.-S. Huang, R. J. Ivison, M. Kim, O. Lefevre, M. Lehnert, C. J. Lonsdale, L. M. Lubin, R. J. Mclure, H. Messias, A. Martínez-Sansigre, A. M. J. Mortier, D. M. Nielsen, M. Ouchi, G. Parish, I. Perez-Fournon, M. Pierre, S. Rawlings, A. Readhead, S. E. Ridgway, D. Rigopoulou, A. K. Romer, I. G. Roseboom, H. J. A. Rottgering, M. Rowan-Robinson, A. Sajina, C. J. Simpson, I. Smail, G. K. Squires, J. A. Stevens, R. Taylor, M. Trichas, T. Urrutia, E. Van Kampen, A. Verma, C. K. Xu

Grant Wilson

We present the Spitzer Extragalactic Representative Volume Survey (SERVS), an 18 square degrees medium-deep survey at 3.6 and 4.5 microns with the post-cryogenic Spitzer Space Telescope to ~2 microJy (AB=23.1) depth of five highly observed astronomical fields (ELAIS-N1, ELAIS-S1, Lockman Hole, Chandra Deep Field South and XMM-LSS). SERVS is designed to enable the study of galaxy evolution as a function of environment from z~5 to the present day, and is the first extragalactic survey both large enough and deep enough to put rare objects such as luminous quasars and galaxy clusters at z>1 into their cosmological context. SERVS is …

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A Panchromatic Catalog Of Early-Type Galaxies At Intermediate Redshift In The Hubble Space Telescope Wide Field Camera 3 Early Release Science Field, M. J. Rutkowski, S. H. Cohen, S. Kaviraj, R. W. O'Connell, N. P. Hathi, R. A. Windhorst, R. E. Ryan Jr., R. M. Crockett, H. Yan, R. A. Kimble, J. Silk, P.J. Mccarthy, A. Koekemoer, B. Balick, H. E. Bond, Daniela Calzetti, M. J. Disney, M. A. Dopita, J. A. Frogel, D. N. B. Hall, J. A. Holtzman, F. Paresce, A. Saha, J. T. Trauger, A. R. Walker, B. C. Whitmore, E. T. Young Jan 2012

A Panchromatic Catalog Of Early-Type Galaxies At Intermediate Redshift In The Hubble Space Telescope Wide Field Camera 3 Early Release Science Field, M. J. Rutkowski, S. H. Cohen, S. Kaviraj, R. W. O'Connell, N. P. Hathi, R. A. Windhorst, R. E. Ryan Jr., R. M. Crockett, H. Yan, R. A. Kimble, J. Silk, P.J. Mccarthy, A. Koekemoer, B. Balick, H. E. Bond, Daniela Calzetti, M. J. Disney, M. A. Dopita, J. A. Frogel, D. N. B. Hall, J. A. Holtzman, F. Paresce, A. Saha, J. T. Trauger, A. R. Walker, B. C. Whitmore, E. T. Young

Daniela Calzetti

In the first of a series of forthcoming publications, we present a panchromatic catalog of 102 visually-selected early-type galaxies (ETGs) from observations in the Early Release Science (ERS) program with the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) of the Great Observatories Origins Deep Survey-South (GOODS-S) field. Our ETGs span a large redshift range, 0.35 < z < 1.5, with each redshift spectroscopically-confirmed by previous published surveys of the ERS field. We combine our measured WFC3 ERS and ACS GOODS-S photometry to gain continuous sensitivity from the rest-frame far-UV to near-IR emission for each ETG. The superior spatial resolution of the HST over this panchromatic baseline allows us to classify the ETGs by their small-scale internal structures, as well as their local environment. By fitting stellar population spectral templates to the broad-band photometry of the ETGs, we determine that the average masses of the ETGs are comparable to the characteristic stellar mass of massive galaxies, 11< log(M [Solar]) < 12. By transforming the observed photometry into the GALEX FUV and NUV, Johnson V, and SDSS g' and r' bandpasses we identify a noteworthy diversity in the rest-frame UV-optical colors and find the mean rest-frame (FUV-V)=3.5 and (NUV-V)=3.3, with 1$\sigma$ standard deviations approximately equal to 1.0. The blue rest-frame UV-optical colors observed for most of the ETGs are evidence for star-formation during the preceding gigayear, but no systems exhibit UV-optical photometry consistent with major recent (<~50 Myr) starbursts. Future publications which address the diversity of stellar populations likely to be present in these ETGs, and the potential mechanisms by which recent star-formation episodes are activated, are discussed.

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The Size-Luminosity Relation At Z=7 In Candels And Its Implication On Reionization, A. Grazian, M. Castellano, A. Fontana, L. Pentericci, J. S. Dunlop, R. J. Mclure, A. M. Koekemoer, M. E. Dickinson, S. M. Faber, H. C. Ferguson, A. Galametz, Mauro Giavalisco, N. A. Grogin, N. P. Hathi, D. D. Kocevski, K. Lai, J. A. Newman, E. Vanzella Jan 2012

The Size-Luminosity Relation At Z=7 In Candels And Its Implication On Reionization, A. Grazian, M. Castellano, A. Fontana, L. Pentericci, J. S. Dunlop, R. J. Mclure, A. M. Koekemoer, M. E. Dickinson, S. M. Faber, H. C. Ferguson, A. Galametz, Mauro Giavalisco, N. A. Grogin, N. P. Hathi, D. D. Kocevski, K. Lai, J. A. Newman, E. Vanzella

Mauro Giavalisco

The exploration of the relation between galaxy sizes and other physical parameters has given important clues to understand the galaxy formation processes. We use the CANDELS Deep+Wide surveys in the GOODS-South, UDS and EGS fields, complemented by data from the HUDF09 program, to address the relation between size and luminosity at z\sim7. We select 153 z-band drop-out galaxies in six different fields characterized by a wide combination of depth and areal coverage, ideally suited to sample without biases the observed size-magnitude plane. Detailed simulations allow us to derive the completeness as a function of sizes and magnitudes and to quantify …

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Molecular Outlfows Identified In The Fcrao Co Survey Of The Taurus Molecular Cloud, Gopal Narayanan, Ronald Snell, Ashley Bemis Jan 2012

Molecular Outlfows Identified In The Fcrao Co Survey Of The Taurus Molecular Cloud, Gopal Narayanan, Ronald Snell, Ashley Bemis

Gopal Narayanan

Jets and outflows are an integral part of the star formation process. While there are many detailed studies of molecular outflows towards individual star-forming sites, few studies have surveyed an entire star-forming molecular cloud for this phenomenon. The 100-deg2 Five College Radio Astronomy Observatory CO survey of the Taurus Molecular Cloud provides an excellent opportunity to undertake an unbiased survey of a large, nearby, molecular cloud complex for molecular outflow activity. Our study provides information on the extent, energetics and frequency of outflows in this region, which are then used to assess the impact of outflows on the parent molecular …

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The Source Counts Of Submillimetre Galaxies Detected At 1.1 Mm, K. S. Scott, Grant 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, J. D. Lowenthal, A. Montaña, K. Nakanishi, T. Oshima, D. Sanders, D. Scott, N. Scoville, Y. Tamura, D. Welch, M. S. Yun, M. Zeballos Jan 2012

The Source Counts Of Submillimetre Galaxies Detected At 1.1 Mm, K. S. Scott, Grant 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, J. D. Lowenthal, A. Montaña, K. Nakanishi, T. Oshima, D. Sanders, D. Scott, N. Scoville, Y. Tamura, D. Welch, M. S. Yun, M. Zeballos

Grant Wilson

The source counts of galaxies discovered at sub-millimetre 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 1.1 mm with AzTEC, totalling 1.6 square degrees in area with root-mean-square depths ranging from 0.4 to 1.7 mJy, and derive the strongest constraints to date on the 1.1 mm source counts at flux densities S(1100) = 1-12 mJy. Using additional data from the AzTEC Cluster Environment Survey to extend the counts to S(1100) ~ 20 mJy, we see tentative evidence for an enhancement relative to the exponential drop …

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Quest For Cosmos Submillimeter Galaxy Counterparts Using Carma And Vla: Identifying Three High-Redshift Starburst Galaxies, V. Smolčić, F. Navarrete, M. Aravena, O. Ilbert, M. S. Yun, K. Sheth, M. Salvato, H. J. Mccracken, Diener C., I. Aretxaga, D. A. Riechers, A. Finoguenov, F. Bertoldi, P. Capak, D. Hughes, A. Karim, E. Schinnerer, N. Z. Scoville, Grant Wilson Jan 2012

Quest For Cosmos Submillimeter Galaxy Counterparts Using Carma And Vla: Identifying Three High-Redshift Starburst Galaxies, V. Smolčić, F. Navarrete, M. Aravena, O. Ilbert, M. S. Yun, K. Sheth, M. Salvato, H. J. Mccracken, Diener C., I. Aretxaga, D. A. Riechers, A. Finoguenov, F. Bertoldi, P. Capak, D. Hughes, A. Karim, E. Schinnerer, N. Z. Scoville, Grant Wilson

Grant Wilson

We report on interferometric observations at 1.3 mm at 2"-3" resolution using the Combined Array for Research in Millimeter-wave Astronomy (CARMA). We identify multi-wavelength counterparts of three submillimeter galaxies (SMGs; F(1mm)>5.5 mJy) in the COSMOS field, initially detected with MAMBO and AzTEC bolometers at low, ~10"-30", resolution. All three sources -- AzTEC/C1, Cosbo-3 and Cosbo-8 -- are identified to coincide with positions of 20 cm radio sources. Cosbo-3, however, is not associated with the most likely radio counterpart, closest to the MAMBO source position, but that further away from it. This illustrates the need for intermediate-resolution (~2") mm-observations to …

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Direct Oxygen Abundances For Low Luminosity Lvl Galaxies, Danielle A. Berg, Evan D. Skillman, Andrew R. Marble, Liese Van Zee, Charles W. Engelbracht, Janice C. Lee, Robert C. Kennicutt Jr., Daniela Calzetti, Daniel A. Dale, Benjamin D. Johnson Jan 2012

Direct Oxygen Abundances For Low Luminosity Lvl Galaxies, Danielle A. Berg, Evan D. Skillman, Andrew R. Marble, Liese Van Zee, Charles W. Engelbracht, Janice C. Lee, Robert C. Kennicutt Jr., Daniela Calzetti, Daniel A. Dale, Benjamin D. Johnson

Daniela Calzetti

We present MMT spectroscopic observations of HII regions in 42 low luminosity galaxies in the LVL. For 31 galaxies, we measured the temperature sensitive [O III] line at a strength of 4 sigma or greater, and thus determine direct oxygen abundances. Our results provide the first direct estimates of oxygen abundance for 19 galaxies. Oxygen abundances were compared to B-band and 4.5 micron luminosities and stellar masses in order to characterize the luminosity-metallicity (L-Z) and mass-metallicity (M-Z) relationships at low-luminosity. We present and analyze a "Combined Select" sample composed of 38 objects (drawn from our parent sample and the literature) …

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Aztec Half Square Degree Survey Of The Shades Fields - Ii. Identifications, Redshifts, And Evidence For Large-Scale Structure, Michał J. Michałowski, J. S. Dunlop, R. J. Ivison, M. Cirasuolo, K. I. Caputi, I. Artexaga, V. Arumugam, J. E. Austermann, E. L. Chapin, S. C. Chapman, K. E. K. Coppin, E. Egami, D. H. Hughes, E. Ibar, A. M. J. Mortier, A. M. Schael, K. S. Scott, I. Smail, T. A. Targett, J. Wagg, Grant Wilson, L. Xu, M. Yun Jan 2012

Aztec Half Square Degree Survey Of The Shades Fields - Ii. Identifications, Redshifts, And Evidence For Large-Scale Structure, Michał J. Michałowski, J. S. Dunlop, R. J. Ivison, M. Cirasuolo, K. I. Caputi, I. Artexaga, V. Arumugam, J. E. Austermann, E. L. Chapin, S. C. Chapman, K. E. K. Coppin, E. Egami, D. H. Hughes, E. Ibar, A. M. J. Mortier, A. M. Schael, K. S. Scott, I. Smail, T. A. Targett, J. Wagg, Grant Wilson, L. Xu, M. Yun

Grant Wilson

The AzTEC 1.1 mm survey of the SCUBA HAlf Degree Extragalactic Survey (SHADES) fields is the largest (0.7 deg2) blank-field millimetre-wavelength survey undertaken to date at a resolution of ~18" and a depth of ~1 mJy. We have used the deep optical-to-radio multi-wavelength data in the SHADES Lockman Hole East and SXDF/UDS fields to obtain galaxy identifications for ~64% (~80% with tentative identifications) of the 148 AzTEC-SHADES 1.1 mm sources, exploiting deep radio and 24 um data complemented by methods based on 8 um flux-density and red optical-infrared (i-K) colour. This unusually high identification rate can be attributed to the …

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Star Formation Laws: The Effects Of Gas Cloud Sampling, Daniela Calzetti, G. Liu, J. Koda Jan 2012

Star Formation Laws: The Effects Of Gas Cloud Sampling, Daniela Calzetti, G. Liu, J. Koda

Daniela Calzetti

Recent observational results indicate that the functional shape of the spatially-resolved star formation-molecular gas density relation depends on the spatial scale considered. These results may indicate a fundamental role of sampling effects on scales that are typically only a few times larger than those of the largest molecular clouds. To investigate the impact of this effect, we construct simple models for the distribution of molecular clouds in a typical star-forming spiral galaxy, and, assuming a power-law relation between SFR and cloud mass, explore a range of input parameters. We confirm that the slope and the scatter of the simulated SFR-molecular …

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