Physical Sciences and Mathematics Commons^™

Infrared And X-Ray Studies Of The Galactic Center, Hui Dong

Open Access Dissertations

The purpose of this dissertation is to locate evolved massive stars within the central 50 pc of the Galactic Center. These stars are considered to be the descendants of O stars and should be less than 10 Myr old. They trace young star clusters within the Galactic Center. Through these stars and young star clusters, we hope to understand the star formation mode and history within the Galactic Center, as well as the properties of evolved massive stars in the high metallicity environment. We first study the Chandra X-ray deep survey of the Arches and Quintuplet clusters, two of the …

H I Asymmetries In The Isolated Galaxy Cig 292, Antonio Portas, Tom C. Scott, Elias Brinks, Albert Bosma, Lourdes Verdes-Montenegro, Volker Heesen, Daniel Espada, Simon Verley, Jack Sulentic, Chandreyee Sengupta, E Athanassoula, Min S. Yun

Min S. Yun

We present Expanded Very Large Array (EVLA) D-array observations of the 21 cm line of neutral hydrogen (H I) of CIG 292, an isolated SA(s)b galaxy at a distance of ~24.3 Mpc. From previous H I single dish observations the galaxy was known to have a mildly asymmetric H I profile (A flux = 1.23 ± 0.3). Our EVLA observations show there is ~12% more H I projected south of the optical center (approaching velocities) than in the north (receding velocities), despite the H I extending ~16% further to the north than the south. The H I projected within the …

Relating Bs Mixing And Bs → Μ+Μ− With New Physics, Eugene Golowich, Joanne Hewett, Sandip Pakvasa, Alexey A. Petrov, Gagik K. Yeghiyan

Eugene Golowich

We perform a study of the Standard Model (SM) fit to the mixing quantities ∆MB_s, and ∆TB_s/∆MB_s in order to bound contributions of New Physics to B_s mixing. We then use this to explore the branching fraction of B_s → μ+μ− in certain models of New Physics (NP). In most cases, this constrains NP amplitudes for B_s → μ+μ− to lie below the SM component.

A Study Of Massive And Evolved Galaxies At High Redshift, H. Nayyeri, B. Mobasher, H. C. Ferguson, S. De Barros, T. Wiklind, T. Dahlen, M. Dickinson, Mauro Giavalisco, A. Fontana, M.L.N. Ashby, G. Barro, Y. Guo, N.P. Hathi, S. Kassin, A. Koekemoer, S. Willner

Mauro Giavalisco

We use data taken as part of HST/WFC3 observations of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) to identify massive and evolved galaxies at 3 < z < 4:5. This is performed using the strength of the Balmer break feature at rest-frame 3648_A, which is a diagnostic of the age of the stellar population in galaxies. Using WFC3 H-band selected catalog for the CANDELS GOODS-S field and deep multi-waveband photometry from optical (HST) to mid- infrared (Spitzer) wavelengths, we identify a population of old and evolved post-starburst galaxies based on the strength of their Balmer breaks (Balmer Break Galaxies- BBGs). The galaxies are also selected to be bright in rest-frame near-IR wavelengths and hence, massive. We identify a total of 16 BBGs. Fitting the spectral energy distribution (SED) of the BBGs show that the candidate galaxies have average estimated ages of ~800 Myr and average stellar masses of _ 5_1010M_, consistent with being old and massive systems. Two of our BBG candidates are also identified by the criteria that is sensitive to star forming galaxies (LBG selection). We find a number density of _ 3:2 _ 10^-5 Mpc^-3 for the BBGs corresponding to a mass density of ~ 2:0x106M. / Mpc3 in the redshift range covering the survey. Given the old age and the passive evolution, it is argued that some of these objects formed the bulk of their mass only a few hundred million years after the Big Bang.

High-Resolution Ultraviolet Spectroscopy Of Gas In Galaxy Halos And Large-Scale Structures, Limin Song

Open Access Dissertations

This dissertation presents spectroscopic studies of gas in galaxy halos and large-scale structures through high-resolution quasar absorption lines. The broad goal of this effort is to learn how galaxies acquire their gas and how they return it to the intergalactic medium, or more generally, how galaxies interact with their environment. The study of the absorption lines due to the extraplanar 21cm "Outer Arm'' (OA) of the Milky Way toward two quasars, H1821+643 and HS0624+6907, provides valuable insight into the gas accretion processes. It yields the following results. (1) The OA is a multiphase cloud and high ions show small but …

Color And Stellar Population Gradients In Passively Evolving Galaxies At Z~2 From Hst/Wfc3 Deep Imaging In The Hubble Ultra Deep Field, Yicheng Guo, Mauro Giavalisco, Paolo Cassata, Henry C. Ferguson, Mark Dickinson, Alvio Renzini, Anton Koekemoer, Norman A. Grogin, Casey Papovich, Elena Tundo, Adriano Fontana, Jennifer M. Lotz, Sara Salimbeni

Mauro Giavalisco

We report the detection of color gradients in six massive (stellar mass > 10^{10} M_{sun}) and passively evolving (specific SFR < 10^{-11}/yr) galaxies at redshift 1.3

Distribution Ofwater Vapor In Molecular Clouds, G Melrick, V Tolls, Ronald L. Snell, E Bergin, D Hollenbach, M Kaufman, D Li, D Neufeld

Astronomy Department Faculty Publication Series

We report the results of a large-area study of water vapor along the Orion Molecular Cloud ridge, the purpose of which was to determine the depth-dependent distribution of gas-phase water in dense molecular clouds. We find that the water vapor measured toward 77 spatial positions along the face-on Orion ridge, excluding positions surrounding the outflow associated with BN/KL and IRc2, display integrated intensities that correlate strongly with known cloud surface tracers such as CN, C₂H, ¹³CO J = 5-4, and HCN, and less well with the volume tracer N₂H⁺. Moreover, at total column …

New Insights Into Galaxy Structure From Galphat– I. Motivation, Methodology And Benchmarks For Sérsic Models, I Yoon, M Weinberg, N Katz

Astronomy Department Faculty Publication Series

We introduce a new galaxy image decomposition tool, galphat (GALaxy PHotometric ATtributes), which is a front-end application of the Bayesian Inference Engine (bie), a parallel Markov chain Monte Carlo package, to provide full posterior probability distributions and reliable confidence intervals for all model parameters. The bie relies on galphat to compute the likelihood function. galphat generates scale-free cumulative image tables for the desired model family with precise error control. Interpolation of this table yields accurate pixellated images with any centre, scale and inclination angle. galphat then rotates the image by position angle using a Fourier shift theorem, yielding high-speed, accurate …

The Murmur Of The Hidden Monster: Chandra's Decadal View Of The Supermassive Black Hole In M31, Z Li, Mr Garcia, Wr Forman, C Jones, Rp Kraft, Dv Lal, Ss Murray, Qd Wang

Astronomy Department Faculty Publication Series

The Andromeda galaxy (M31) hosts a central supermassive black hole (SMBH), known as M31*, which is remarkable for its mass (~10⁸ M ) and extreme radiative quiescence. Over the past decade, the Chandra X-Ray Observatory has pointed to the center of M31 ~100 times and accumulated a total exposure of ~900 ks. Based on these observations, we present an X-ray study of a highly variable source that we associate with M31* based on positional coincidence. We find that M31* remained in a quiescent state from late 1999 to 2005, exhibiting an average 0.5-8 keV luminosity 10³⁶ erg s …

Title: Properties Of The Compact Hii Region Complex G-0.02-0.07, E Mills, Mr Morris, C Lang, H Dong, Qd Wang, A Cotera, S Stolovy

Astronomy Department Faculty Publication Series

Abstract: We present new extinction maps and high-resolution Paschen alpha images of G-0.02-0.07, a complex of compact HII regions located adjacent to the M-0.02-0.07 giant molecular cloud, 6 parsecs in projection from the center of the Galaxy. These HII regions, which lie in projection just outside the boundary of the Sgr A East supernova remnant, represent one of the most recent episodes of star formation in the central parsecs of the Galaxy. The 1.87 micron extinctions of regions A, B and C are almost identical, approximately 1.5 magnitudes. Region D, in contrast, has a peak 1.87 micron extinction of 2.3 …

A Green Bank Telescope Survey For H I 21 Cm Absorption In The Disks And Halos Of Low-Redshift Galaxies*, S Borthakur, Tm Tripp, Min Yun, Dv Bowen, Jd Meiring, Dg York, E Momjian

Astronomy Department Faculty Publication Series

We present an H I 21 cm absorption survey with the Green Bank Telescope (GBT) of galaxy-quasar pairs selected by combining galaxy data from the Sloan Digital Sky Survey (SDSS) and radio sources from the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST) survey. Our sample consists of 23 sight lines through 15 low-redshift foreground galaxy-background quasar pairs with impact parameters ranging from 1.7 kpc up to 86.7 kpc. We detected one absorber in the GBT survey from the foreground dwarf galaxy, GQ1042+0747, at an impact parameter of 1.7 kpc and another possible absorber in our follow-up Very Large …

Evidence For 1000 Km S–1 Molecular Outflows In The Local Ulirg Population, A Chung, Min Yun, Gopal Narayanan, M Heyer, Nr Erickson

Astronomy Department Faculty Publication Series

The feedback from galactic outflows is thought to play an important role in shaping the gas content, star formation history, and ultimately the stellar mass function of galaxies. Here we present evidence for massive molecular outflows associated with ultra-luminous infrared galaxies (ULIRGs) in the co-added Redshift Search Receiver ¹²CO (1-0) spectrum. Our stacked spectrum of 27 ULIRGs at z = 0.043-0.11 (ν_rest = 110-120 GHz) shows broad wings around the CO line with ΔV(FWZI) 2000 km s^–1. Its integrated line flux accounts for up to 25% ± 5% of the total CO line luminosity. …

On The Clustering Of Sub-Millimeter Galaxies, Cc Williams, M Giavalisco, C Porciani, Min Yun, A Pope, Ks Scott, Je Austermann, I Aretxaga, B Hatsukade, K-S Lee, Gw Wilson, Jr Cybulski, Dh Hughes, R Kawabe, K Kohno, T Perera, Fp Schloerb

Astronomy Department Faculty Publication Series

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.

A Wfc3 Study Of Globular Clusters In Ngc 4150 - An Early-Type Minor Merger, Sugata Kaviraj, R. Mark Crockett, Bradley C. Whitmore, Joseph Silk, Robert W. O'Connell, Rogier A. Windhorst, Max Mutchler, Marina Rejkuba, Sukyoung Yi, Jay A. Frogel, Daniela Calzetti

Daniela Calzetti

We combine near-ultraviolet (NUV; 2250 {\AA}) and optical (U, B, V, I) imaging from the Wide Field Camera 3 (WFC3), on board the Hubble Space Telescope (HST), to study the globular cluster (GC) population in NGC 4150, a sub-L* (M_B ~ -18.48 mag) early-type minor-merger remnant in the Coma I cloud. We use broadband NUV-optical photometry from the WFC3 to estimate individual ages, metallicities, masses and line-of-sight extinctions [E_(B-V)] for 63 bright (M_V < -5 mag) GCs in this galaxy. In addition to a small GC population with ages greater than 10 Gyr, we find a dominant population of clusters with ages centred around 6 Gyr, consistent with the expected peak of stellar mass assembly in faint early-types residing in low-density environments. The old and intermediate-age GCs in NGC 4150 are metal-poor, with metallicities less than 0.1 ZSun, and reside in regions of low extinction (E_(B-V) < 0.05 mag). We also find a population of young, metal-rich (Z > 0.3 ZSun) clusters that have formed within the last Gyr and reside in relatively dusty (E_(B-V) > 0.3 mag) regions that are coincident with the part of the …

The Herschel M33 Extended Survey (Herm33es): Pacs Spectroscopy Of The Star Forming Region Bclmp 302, B. Mookerjea, C. Kramer, C. Buchbender, M. Boquien, S. Verley, M. Relaño, G. Quintana-Lacaci, S. Aalto, J. Braine, Daniela Calzetti, F. Combes, S. Garcia-Burillo, P. Gratier, C. Henkel, F. Israel, S. Lord, T. Nikola, M. Rölling, G. Stacey, F. S. Tabatabaei, F. Van Der Tak, P. Van Der Werf

Daniela Calzetti

Context: The emission line of [CII] at 158 micron is one of the strongest cooling lines of the interstellar medium (ISM) in galaxies. Aims: Disentangling the relative contributions of the different ISM phases to [CII] emission, is a major topic of the HerM33es program, a Herschel key project to study the ISM in the nearby spiral galaxy M33. Methods: Using PACS, we have mapped the emission of [CII] 158 micron, [OI] 63 micron, and other FIR lines in a 2'x2' region of the northern spiral arm of M33, centered on the HII region BCLMP302. At the peak of H-alpha emission, …

How Do Star-Forming Galaxies At Z>3 Assemble Their Masses?, Kyoung-Soo Lee, Henry C. Ferguson, Tommy Wiklind, Tomas Dahlen, Mark E. Dickinson, Mauro Giavalisco, Normin Grogin, Casey Papovich, Hugo Messias, Yicheng Guo, Lihwai Lin

Mauro Giavalisco

We investigate how star-forming galaxies typically assemble their masses at high redshift. Using the deep multi-wavelength coverage of the GOODS dataset, we measure stellar mass of a large sample of star-forming galaxies at z~4 and 5, and make a robust determination of stellar mass function (SMF). We report a broad correlation between stellar mass and UV luminosity, such that more UV-luminous galaxies are, on average, more massive. However, the correlation has a substantial intrinsic scatter evidenced by a non-negligible number of UV-faint but massive galaxies. Furthermore, the low-mass end of the SMF does not rise as steeply as the UV …

Variation In The Dust Spectral Index Across M33, Fatemeh S. Tabatabaei, Jonathan Braine, Carsten Kramer, Manolis Xilouris, Mederic Boquien, Simon Verley, Eva Schinnerer, Daniela Calzetti, Francoise Combes, Frank Israel, Christian Henkel, The Herm33es Team

Daniela Calzetti

Using the Herschel PACS and SPIRE FIR/submm data, we investigate variations in the dust spectral index $\beta$ in the nearby spiral galaxy M33 at a linear resolution of 160 pc. We use an iteration method in two different approaches, single and two-component modified black body models. In both approaches, $\beta$ is higher in the central disk than in the outer disk similar to the dust temperature. There is a positive correlation between $\beta$ and Halpha as well as with the molecular gas traced by CO(2-1). A Monte-Carlo simulation shows that the physical parameters are better constrained when using the two-component …

Spectral Energy Distributions Of A Set Of Hii Regions In M33 (Herm33es), M. Relaño, S. Verley, I. Pérez, C. Kramer, E. M. Xilouris, M. Boquien, J. Braine, Daniela Calzetti, C. Henkel, Herm33s Team

Daniela Calzetti

Within the framework of the HerM33es Key Project for Herschel and in combination with multi-wavelength data, we study the Spectral Energy Distribution (SED) of a set of HII regions in the Local Group Galaxy M33. Using the Halpha emission, we perform a classification of a selected HII region sample in terms of morphology, separating the objects in filled, mixed, shell and clear shell objects. We obtain the SED for each HII region as well as a representative SED for each class of objects. We also study the emission distribution of each band within the regions. We find different trends in …

Temperature Variations Of The Cold Dust In The Triangulum Galaxy M33, S. Komugi, T. Tosaki, K. Kohno, T. Tsukagoshi, K. Nakanishi, T. Sawada, R. Kawabe, H. Ezawa, N. Kuno, S. Onodera, Y. Tamura, Grant Wilson, M. S. Yun, K. Scott, T. A. Perera, J. E. Austermann, D. H. Hughes, I. Aretxaga, K. Tanaka, K. Muraoka, R. Miura, F. Egusa

Grant Wilson

We present wide-field 1.1 mm continuum imaging of the nearby spiral galaxy M 33, conducted with the AzTEC bolometer camera on ASTE. We show that the 1.1 mm flux traces the distribution of dust with T ~20 K. Combined with far-infrared imaging at 160um, we derive the dust temperature distribution out to a galactic radius of ~7 kpc with a spatial resolution of ~100 parsecs. Although the 1.1 mm flux is observed predominantly near star forming regions, we find a smooth radial temperature gradient declining from ~20 K to ~13 K, consistent with recent results from the Herschel satellite. Further …

The Redshift Search Receiver 3 Mm Wavelength Spectra Of 10 Galaxies, Ronald L. Snell, Gopal Narayanan, Min S. Yun, Mark Heyer, Aeree Chung, William M. Irvine, Neal R. Erickson, Guilin Liu

Gopal Narayanan

The 3 mm wavelength spectra of 10 galaxies have been obtained at the Five College Radio Astronomy Observatory using a new, very broadband receiver and spectrometer, called the Redshift Search Receiver (RSR). The RSR has an instantaneous bandwidth of 37 GHz covering frequencies from 74 to 111 GHz and has a spectral resolution of 31 MHz (~100 km s–1). During tests of the RSR on the FCRAO 14 m telescope the complete 3 mm spectra of the central regions of NGC 253, Maffei 2, NGC1068, IC 342, M82, NGC 3079, NGC 3690, NGC 4258, Arp 220, and NGC 6240 were …

Multi-Wavelength View Of Kiloparsec-Scale Clumps In Star-Forming Galaxies At Z~2, Yicheng Guo, Mauro Giavalisco, Henry C. Ferguson, Paolo Cassata, Anton M. Koekemoer

Mauro Giavalisco

This paper studies the properties of kiloparsec-scale clumps in star-forming galaxies at z~2 through multi-wavelength broad band photometry. A sample of 40 clumps is identified through auto-detection and visual inspection from 10 galaxies with 1.5

Kingfish -- Key Insights On Nearby Galaxies: A Far-Infrared Survey With Herschel: Survey Description And Image Atlas, R. C. Kennicutt, Daniela Calzetti, G. Aniano, P. Appleton, L. Armus, P. Beirão, A. D. Bolatto, B. Brandl, A. Crocker, K. Croxall, D. A. Dale, J. Donovan Meyer, B. T. Draine, C. W. Engelbracht, M. Galametz, K. D. Gordon, B. Groves, C.-N. Hao, G. Helou, J. Hinz, L. K. Hunt, B. Johnson, J. Koda, O. Krause, A. K. Leroy, Y. Li, S. Meidt, E. Montiel, E. J. Murphy, N. Rahman, H.-W. Rix, H. Roussel, K. Sandstrom, M. Sauvage, E. Schinnerer, K. Skibba, J. D. T. Smith, S. Srinivasan, L. Virgroux, F. Walter, C. D. Wilson, M. Wolfire, S. Zibetti

Daniela Calzetti

The KINGFISH project (Key Insights on Nearby Galaxies: a Far-Infrared Survey with Herschel) is an imaging and spectroscopic survey of 61 nearby (d < 30 Mpc) galaxies, chosen to cover a wide range of galaxy properties and local interstellar medium (ISM) environments found in the nearby Universe. Its broad goals are to characterize the ISM of present-day galaxies, the heating and cooling of their gaseous and dust components, and to better understand the physical processes linking star formation and the ISM. KINGFISH is a direct descendant of the Spitzer Infrared Nearby Galaxies Survey (SINGS), which produced complete Spitzer imaging and spectroscopic mapping and a comprehensive set of multi-wavelength ancillary observations for the sample. The Herschel imaging consists of complete maps for the galaxies at 70, 100, 160, 250, 350, and 500 microns. The spectal line imaging of the principal atomic ISM cooling lines ([OI]63um, [OIII]88um, [NII]122,205um, and [CII]158um) covers the subregions in the centers and disks that already have been mapped in the mid-infrared with Spitzer. The KINGFISH and SINGS multi-wavelength datasets combined provide panchromatic mapping of the galaxies sufficient to resolve individual star-forming regions, and tracing the important heating and cooling channels of the ISM, across a wide range of local extragalactic ISM environments. This paper summarizes the scientific strategy for KINGFISH, the properties of the galaxy sample, the observing strategy, and data processing and products. It also presents a combined Spitzer and Herschel image atlas for the KINGFISH galaxies, covering the wavelength range 3.6 -- 500 microns. All imaging and spectroscopy data products will be released to the Herschel user generated product archives.

Aztec 1.1 Mm Images Of 16 Radio Galaxies At 0.5, A. Humphrey, M. Zeballos, I. Aretxaga, D. H. Hughes, M. S. Yun, R. Cybulski, Grant Wilson, J. Austermann, H. Ezawa, R. Kawabe, K. Kohno, T. Perera, K. Scott, D. Sánchez-Arguelles, R. Gutermuth

Grant Wilson

We present 1.1 mm observations for a sample of 16 powerful radio galaxies at 0.5

Candels: The Evolution Of Galaxy Rest-Frame Ultraviolet Colors From Z = 8 To 4, Steven L. Finkelstein, Casey Papovich, Brett Salmon, Kristian Finlator, Mark Dickinson, Henry C. Ferguson, Mauro Giavalisco, Anton M. Koekemoer, Naveen A. Reddy, Robert Bassett, Christopher J. Conselice, James C. Dunlop, S. M. Faber, Norman A. Grogin, Nimish P. Hathi, Dale D. Kocevski, Kamson Lai, Kyoung-Soo Lee, Ross J. Mclure, Bahram Mobasher, Jeffrey A. Newman

Mauro Giavalisco

We study the evolution of galaxy rest-frame ultraviolet (UV) colors in the epoch 4 < z < 8. We use new wide-field near-infrared data in GOODS-S from the CANDELS, HUDF09 and ERS programs to select galaxies via photometric redshift measurements. Our sample consists of 2812 candidate galaxies at z > 3.5, including 113 at z = 7 to 8. We fit the observed spectral energy distribution to a suite of synthetic stellar population models, and measure the value of the UV spectral slope (beta) from the best-fit model spectrum. The median value of beta evolves significantly from -1.82 (+0.00,-0.04) at z = 4, to -2.37 (+0.26,-0.06) at z = 7. Additionally, we find that faint galaxies at z = 7 have beta = -2.68 (+0.39,-0.24) (~ -2.4 after correcting for observational bias); this is redder than …

Deep 1.1 Mm-Wavelength Imaging Of The Goods-South Field By Aztec/Aste -- Ii. Redshift Distribution And Nature Of The Submillimetre Galaxy Population, Min S. Yun, K. S. Scott, Yicheng Guo, I. Aretxaga, Mauro Giavalisco, J. E. Aistermann, P. Capak, Yuxi Chen, H. Ezawa, B. Hatsukade, D. H. Hughes, D. Iono, R. Kawabe, K. Kohno, J. Lowenthal, N. Miller, G. Morrison, T. Oshima, T. A. Perera, M. Salvato, J. Silverman, Y. Tamura, C. C. Williams, G. W. Wilson

Mauro Giavalisco

We report the results of the counterpart identification and a detailed analysis of the physical properties of the 48 sources discovered in our deep 1.1mm wavelength imaging survey of the GOODS-South field using the AzTEC instrument on the Atacama Submillimeter Telescope Experiment (ASTE). One or more robust or tentative counterpart candidate is found for 27 and 14 AzTEC sources, respectively, by employing deep radio continuum, Spitzer MIPS & IRAC, and LABOCA 870 micron data. Five of the sources (10%) have two robust counterparts each, supporting the idea that these galaxies are strongly clustered and/or heavily confused. Photometric redshifts and star …

Dust-Corrected Star Formation Rates Of Galaxies. Ii. Combinations Of Ultraviolet And Infrared Tracers, Cai-Na Hao, C. Kennicutt Kr., Benjamin D. Johnson, Daniela Calzetti, Daniel A. Dale, John Moustakas

Daniela Calzetti

We present new calibrations of far-ultraviolet (FUV) attenuation as derived from the total infrared to FUV luminosity ratio (IRX) and the FUV-NUV color. We find that the IRX-corrected FUV luminosities are tightly and linearly correlated with the attenuation-corrected H\alpha\ luminosities (as measured from the Balmer decrement), with a rms scatter of $\pm 0.09$ dex. The ratios of these attenuation-corrected FUV to H\alpha\ luminosities are consistent with evolutionary synthesis model predictions, assuming a constant star formation rate over 100 Myr, solar metallicity and either a Salpeter or a Kroupa IMF with lower and upper mass limits of 0.1 and 100\msun. The …

Aztec 1.1 Mm Observations Of The Mbm12 Molecular Cloud, M. J. Kim, S. Kim, S. Youn, M. S. Yun, Grant Wilson, I. Aretxaga, J. P. Williams, D. H. Hughes, A. Humphrey, J. E. Austermann, T. A. Perera, P. D. Mauskopf, L. Magnani, Y.-W. Kang

Grant Wilson

We present 1.1 mm observations of the dust continuum emission from the MBM12 high-latitude molecular cloud observed with the Astronomical Thermal Emission Camera (AzTEC) mounted on the James Clerk Maxwell Telescope on Mauna Kea, Hawaii. We surveyed a 6.34 deg$^2$ centered on MBM12, making this the largest area that has ever been surveyed in this region with submillimeter and millimeter telescopes. Eight secure individual sources were detected with a signal-to-noise ratio of over 4.4. These eight AzTEC sources can be considered to be real astronomical objects compared to the other candidates based on calculations of the false detection rate. The …

Candels: The Progenitors Of Compact Quiescent Galaxies At Z 2, Guillermo Barro, S. M. Faber, Pablo G. P´Erez-Gonz´Alez, David C. Koo, Christina C. Williams, Dale D. Kocevski, Jonathan R. Trump, Mark Mozena, Elizabeth Mcgrath, Arjen Van Der Wel, Stijn Wuyts, Eric F. Bell, Darren J. Croton, Avishai Dekel, M. L. N. Ashby, Henry C. Ferguson, Adriano Fontana, Mauro Giavalisco, Norman A. Grogin, Yicheng Guo, Nimish P. Hathi, Philip F. Hopkins, Kuang-Han Huang, Anton M. Koekemoer, Jeyhan S. Kartaltepe, Kyoung-Soo Lee, Jeffrey A. Newman, Lauren A. Porter, Joel R. Primack, Russell E. Ryan, David Rosario, Rachel S. Somerville

Mauro Giavalisco

We combine high-resolution HST/WFC3 images with multi-wavelength photometry to track the evolution of structure and activity of massive (log(M*) > 10) galaxies at redshifts z = 1.4 - 3 in two fields of the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS). We detect compact, star-forming galaxies (cSFGs) whose number densities, masses, sizes, and star formation rates qualify them as likely progenitors of compact, quiescent, massive galaxies (cQGs) at z = 1.5 - 3. At z > 2 most cSFGs have specific star-formation rates (sSFR = 10^-9 yr^-1) half that of typical, massive SFGs at the same epoch, and host X-ray luminous …

What Turns Galaxies Off? The Different Morphologies Of Star-Forming And Quiescent Galaxies Since Z~2 From Candels, Eric F. Bell, Arjen Van Der Wel, Casey Papovich, Dale Kocevski, Jennifer Lotz, Daniel H. Mcintosh, Jeyhan Kartaltepe, S. M. Faber, Harry Ferguson, Anton Koekemoer, Norman Grogin, Stijn Wuyts, Edmond Cheung, Christopher J. Conselice, Avishai Dekel, James S. Dunlop, Mauro Giavalisco, Mauro Giavalisco, Jessica Herrington, David C. Koo, Elizabeth J. Mcgrath, Duilia De Mello, Hans-Walter Rix, Aday R. Robaina, Christina C. Williams

Mauro Giavalisco

We use HST/WFC3 imaging from the CANDELS Multicycle Treasury Survey, in conjunction with the Sloan Digital Sky Survey, to explore the evolution of galactic structure for galaxies with stellar masses >3e10M_sun from z=2.2 to the present epoch, a time span of 10Gyr. We explore the relationship between rest-frame optical color, stellar mass, star formation activity and galaxy structure. We confirm the dramatic increase from z=2.2 to the present day in the number density of non-star-forming galaxies above 3e10M_sun reported by others. We further find that the vast majority of these quiescent systems have concentrated light profiles, as parametrized by the …

The Resolved Stellar Population In 50 Regions Of M83 From Hst/Wfc3 Early Release Science Observations, Hwihyun Kim, Bradley C. Whitmore, Rupali Chandar, Abhijit Saha, Catherine C. Kaleida, Max Mutchler, Seth H. Cohen, Daniela Calzetti, Robert W. O'Connel, Rogier A. Windhorst, Bruce Balick, Howard E. Bond, C. Marcella Carollo, Michael J. Disney, Michael A. Dopita, Jay A. Frogel, Donald N. B. Hall, Jon A. Holtzman, Randy A. Kimble, Patrick J. Mccarthy, Francesco Paresce, Joe I. Silk, John T. Trauger, Alistair R. Walker, Erick T. Young

Daniela Calzetti

We present a multi-wavelength photometric study of ~15,000 resolved stars in the nearby spiral galaxy M83 (NGC5236, D=4.61Mpc) based on Hubble Space Telescope Wide Field Camera 3 observations using four filters: F336W, F438W, F555W, and F814W. We select 50 regions (an average size of 260 pc by 280 pc) in the spiral arm and inter-arm areas of M83, and determine the age distribution of the luminous stellar populations in each region. This is accomplished by correcting for extinction towards each individual star by comparing its colors with predictions from stellar isochrones. We compare the resulting luminosity weighted mean ages of …