Open Access. Powered by Scholars. Published by Universities.®
![Digital Commons Network](http://assets.bepress.com/20200205/img/dcn/DCsunburst.png)
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Institution
- Publication
- Publication Type
Articles 1 - 30 of 30
Full-Text Articles in Physical Sciences and Mathematics
Galaxy Zoo: Candels Barred Discs And Bar Fractions, B. D. Simmons, Thomas Melvin, Chris Lintott, Karen L. Masters, Kyle W. Willett, William C. Keel, R. J. Smethurst, Edmond Cheung, Robert C. Nichol, Kevin Schawinski, Michael Rutkowski, Jeyhan S. Kartaltepe, Eric F. Bell, Kevin R. V. Casteels, Christopher J. Conselice, Omar Almaini, Henry C. Ferguson, Lucy Fortson, William Hartley, Dale D. Kocevski, Anton M. Koekemoer, Daniel H. Mcintosh, Alice Mortlock, Jeffrey A. Newman, Jamie Owensworth, Steven Bamford, Tomas Dahlen, Sandra M. Faber, Steven L. Finkelstein, Adriano Fontana, Audrey Galametz, N. A. Grogin, Ruth Grützbauch, Yicheng Guo, Boris Häußler, Kian J. Jek, Sugata Kaviraj, Ray A. Lucas, Michael Peth, Mara Salvato, Tommy Wiklind, Stijn Wuyts
Galaxy Zoo: Candels Barred Discs And Bar Fractions, B. D. Simmons, Thomas Melvin, Chris Lintott, Karen L. Masters, Kyle W. Willett, William C. Keel, R. J. Smethurst, Edmond Cheung, Robert C. Nichol, Kevin Schawinski, Michael Rutkowski, Jeyhan S. Kartaltepe, Eric F. Bell, Kevin R. V. Casteels, Christopher J. Conselice, Omar Almaini, Henry C. Ferguson, Lucy Fortson, William Hartley, Dale D. Kocevski, Anton M. Koekemoer, Daniel H. Mcintosh, Alice Mortlock, Jeffrey A. Newman, Jamie Owensworth, Steven Bamford, Tomas Dahlen, Sandra M. Faber, Steven L. Finkelstein, Adriano Fontana, Audrey Galametz, N. A. Grogin, Ruth Grützbauch, Yicheng Guo, Boris Häußler, Kian J. Jek, Sugata Kaviraj, Ray A. Lucas, Michael Peth, Mara Salvato, Tommy Wiklind, Stijn Wuyts
Physics and Astronomy Faculty Publications
The formation of bars in disc galaxies is a tracer of the dynamical maturity of the population.
The remainder of the abstract is available at:
http://dx.doi.org/10.1093/mnras/stu1817
The Double Galaxy Cluster Abell 2465 – Ii. Star Formation In The Cluster, Gary A. Wegner, Devin S. Chu, Ho Seong Hwang
The Double Galaxy Cluster Abell 2465 – Ii. Star Formation In The Cluster, Gary A. Wegner, Devin S. Chu, Ho Seong Hwang
Dartmouth Scholarship
We investigate the star formation rate and its location in the major merger cluster Abell 2465 at z = 0.245. Optical properties of the cluster are described in Paper I. Measurements of the Hα and infrared dust emission of galaxies in the cluster were made with an interference filter centred on the redshifted line at a wavelength of 817 nm and utilized data from the WISE satellite 12 μm band. Imaging in the Johnson U and B bands was obtained, and along with SDSS u and r was used to study the blue fraction, which appears enhanced, as a further …
Vimos Ultra-Deep Survey (Vuds): Witnessing The Assembly Of A Massive Cluster At Z ~ 3.3, B. C. Lemaux, O. Cucciati, L. A. M. Tasca, O. Le Fèvre, G. Zamorani, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, R. Amorín, S. Bardelli, P. Capak, L. P. Cassarà, M. Castellano, A. Cimatti, J. G. Cuby, S. De La Torre, A. Durkalec, A. Fontana, M. Giavalisco, A. Grazian, N. P. Hathi, O. Ilbert, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P. W. Wang, S. Charlot, T. Contini, S. Fotopoulou, R. R. Gal, Dale D. Kocevski, C. López-Sanjuan, L. M. Lubin, Y. Mellier, T. Sadibekova, N. Scoville
Vimos Ultra-Deep Survey (Vuds): Witnessing The Assembly Of A Massive Cluster At Z ~ 3.3, B. C. Lemaux, O. Cucciati, L. A. M. Tasca, O. Le Fèvre, G. Zamorani, P. Cassata, B. Garilli, V. Le Brun, D. Maccagni, L. Pentericci, R. Thomas, E. Vanzella, R. Amorín, S. Bardelli, P. Capak, L. P. Cassarà, M. Castellano, A. Cimatti, J. G. Cuby, S. De La Torre, A. Durkalec, A. Fontana, M. Giavalisco, A. Grazian, N. P. Hathi, O. Ilbert, C. Moreau, S. Paltani, B. Ribeiro, M. Salvato, D. Schaerer, M. Scodeggio, V. Sommariva, M. Talia, Y. Taniguchi, L. Tresse, D. Vergani, P. W. Wang, S. Charlot, T. Contini, S. Fotopoulou, R. R. Gal, Dale D. Kocevski, C. López-Sanjuan, L. M. Lubin, Y. Mellier, T. Sadibekova, N. Scoville
Physics and Astronomy Faculty Publications
Using new spectroscopic observations obtained as part of the VIMOS Ultra-Deep Survey (VUDS), we performed a systematic search for overdense environments in the early universe (z> 2) and report here on the discovery of Cl J0227-0421, a massive protocluster at z = 3.29. This protocluster is characterized by both the large overdensity of spectroscopically confirmed members, δgal = 10.5 ± 2.8, and a significant overdensity in photometric redshift members. The halo mass of this protocluster is estimated by a variety of methods to be ~3 × 1014ℳ⊙ at z ~ 3.3, which, evolved to z …
Hidden Starbursts And Active Galactic Nuclei At 0 < Z < 4 From The Herschel-Vvds-Cfhtls-D1 Field: Inferences On Coevolution And Feedback, B. C. Lemaux, E. Le Foc'h, O. Le Fèvre, O. Ilbert, L. Tresse, L. M. Lubin, G. Zamorani, R. R. Gal, P. Ciliegi, P. Cassata, Dale D. Kocevski, E. J. Mcgrath, S. Bardelli, E. Zucca, G. K. Squires
Hidden Starbursts And Active Galactic Nuclei At 0 < Z < 4 From The Herschel-Vvds-Cfhtls-D1 Field: Inferences On Coevolution And Feedback, B. C. Lemaux, E. Le Foc'h, O. Le Fèvre, O. Ilbert, L. Tresse, L. M. Lubin, G. Zamorani, R. R. Gal, P. Ciliegi, P. Cassata, Dale D. Kocevski, E. J. Mcgrath, S. Bardelli, E. Zucca, G. K. Squires
Physics and Astronomy Faculty Publications
We investigate of the properties of ~2000 Herschel/SPIRE far-infrared-selected galaxies from 0 < z < 4 in the CFHTLS-D1 field. Using a combination of extensive spectroscopy from the VVDS and ORELSE surveys, deep multiwavelength imaging from CFHT, VLA, Spitzer, XMM-Newton, and Herschel, and well-calibrated spectral energy distribution fitting, Herschel-bright galaxies are compared to optically-selected galaxies at a variety of redshifts. Herschel-selected galaxies are observed to span a range of stellar masses, colors, and absolute magnitudes equivalent to galaxies undetected in SPIRE. Though many Herschel galaxies appear to be in transition, such galaxies are largely consistent with normal star-forming galaxies when rest-frame colors are utilized. The nature of the star-forming “main sequence” is studied and we warn against adopting this …
Understanding Higher-Order Nonlocal Halo Bias At Large Scales By Combining The Power Spectrum With The Bispectrum, Shun Saito, Tobias Baldauf, For Full List Of Authors, See Publisher's Website.
Understanding Higher-Order Nonlocal Halo Bias At Large Scales By Combining The Power Spectrum With The Bispectrum, Shun Saito, Tobias Baldauf, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
Understanding the relation between underlying matter distribution and biased tracers such as galaxies or dark matter halos is essential to extract cosmological information from ongoing or future galaxy redshift surveys. At sufficiently large scales such as the baryon acoustic oscillation (BAO) scale, a standard approach for the bias problem on the basis of the perturbation theory (PT) is to assume the "local bias" model in which the density field of biased tracers is deterministically expanded in terms of matter density field at the same position. The higher-order bias parameters are then determined by combining the power spectrum with higher-order statistics …
Line-Driven Radiative Outflows In Luminous Quasars, Rebecca A. A. Bowler, Paul C. Hewett, James T. Allen, Gary J. Ferland
Line-Driven Radiative Outflows In Luminous Quasars, Rebecca A. A. Bowler, Paul C. Hewett, James T. Allen, Gary J. Ferland
Physics and Astronomy Faculty Publications
An analysis of ≃19 500 narrow ( ≲ 200 km s−1) C iv λλ1548.2,1550.8 absorbers in ≃34 000 Sloan Digital Sky Survey quasar spectra is presented. The statistics of the number of absorbers as a function of outflow velocity shows that in approximately two-thirds of outflows, with multiple C iv absorbers present, absorbers are line-locked at the 500 km s−1 velocity separation of the C iv absorber doublet; appearing as ‘triplets’ in the quasar spectra. Line-locking is an observational signature of radiative line-driving in outflowing material, where the successive shielding of ‘clouds’ of material in the outflow …
Candels/Goods-S, Cdfs, And Ecdfs: Photometric Redshifts For Normal And X-Ray-Detected Galaxies, Li-Ting Hsu, Mara Salvato, Kirpal Nandra, Marcella Brusa, Ralf Bender, Johannes Buchner, Jennifer L. Dooley, Dale D. Kocevski, Yicheng Guo, Nimish P. Hathi, Cyprian Rangel, S. P. Willner, Murray Brightman, Antonis Georgakakis, Tamás Budavári, Alexander S. Szalay, Matthew L.N. Ashby, Guillermo Barro, Tomas Dahlen, Sandra M. Faber, Henry C. Ferguson, Audrey Galametz, Andrea Grazian, Norman A. Grogin, Kuang-Han Huang, Anton M. Koekemoer, Ray A. Lucas, Elizabeth Mcgrath, Bahram Mobasher, Michael Peth, David J. Rosario, Jonathan R. Trump
Candels/Goods-S, Cdfs, And Ecdfs: Photometric Redshifts For Normal And X-Ray-Detected Galaxies, Li-Ting Hsu, Mara Salvato, Kirpal Nandra, Marcella Brusa, Ralf Bender, Johannes Buchner, Jennifer L. Dooley, Dale D. Kocevski, Yicheng Guo, Nimish P. Hathi, Cyprian Rangel, S. P. Willner, Murray Brightman, Antonis Georgakakis, Tamás Budavári, Alexander S. Szalay, Matthew L.N. Ashby, Guillermo Barro, Tomas Dahlen, Sandra M. Faber, Henry C. Ferguson, Audrey Galametz, Andrea Grazian, Norman A. Grogin, Kuang-Han Huang, Anton M. Koekemoer, Ray A. Lucas, Elizabeth Mcgrath, Bahram Mobasher, Michael Peth, David J. Rosario, Jonathan R. Trump
Physics and Astronomy Faculty Publications
We present photometric redshifts and associated probability distributions for all detected sources in the Extended Chandra Deep Field South (ECDFS). This work makes use of the most up-to-date data from the Cosmic Assembly Near-IR Deep Legacy Survey (CANDELS) and the Taiwan ECDFS Near-Infrared Survey (TENIS) in addition to other data. We also revisit multi-wavelength counterparts for published X-ray sources from the 4 Ms CDFS and 250 ks ECDFS surveys, finding reliable counterparts for 1207 out of 1259 sources (~96%). Data used for photometric redshifts include intermediate-band photometry deblended using the TFIT method, which is used for the first time in …
The Mass Evolution Of The First Galaxies: Stellar Mass Functions And Star Formation Rates At 4 < Z < 7 In The Candels Goods-South Field, K. Duncan, C. J. Conselice, A. Mortlock, W. G. Hartley, Y. Guo, H. C. Ferguson, R. Davé, Y. Lu, J. Owensworth, M. L. N. Ashby, A. Dekel, M. Dickinson, S. Faber, M. Giavalisco, N. Grogin, Dale D. Kocevski, A. Koekemoer, R. S. Somerville, C. E. White
The Mass Evolution Of The First Galaxies: Stellar Mass Functions And Star Formation Rates At 4 < Z < 7 In The Candels Goods-South Field, K. Duncan, C. J. Conselice, A. Mortlock, W. G. Hartley, Y. Guo, H. C. Ferguson, R. Davé, Y. Lu, J. Owensworth, M. L. N. Ashby, A. Dekel, M. Dickinson, S. Faber, M. Giavalisco, N. Grogin, Dale D. Kocevski, A. Koekemoer, R. S. Somerville, C. E. White
Physics and Astronomy Faculty Publications
We measure new estimates for the galaxy stellar mass function and star formation rates for samples of galaxies at z ∼ 4, 5, 6 and 7 using data in the CANDELS GOODS South field. The deep near-infrared observations allow us to construct the stellar mass function at z ≥ 6 directly for the first time. We estimate stellar masses for our sample by fitting the observed spectral energy distributions with synthetic stellar populations, including nebular line and continuum emission. The observed UV luminosity functions for the samples are consistent with previous observations; however, we find that the observed MUV …
Keck-I Mosfire Spectroscopy Of Compact Star-Forming Galaxies At Z ≳ 2: High Velocity Dispersions In Progenitors Of Compact Quiescent Galaxies, Guillermo Barro, Jonathan R. Trump, David C. Koo, Avishai Dekel, Susan A. Kassin, Dale D. Kocevski, Sandra M. Faber, Arjen Van Der Wel, Yicheng Guo, Pablo G. Pérez-González, Elisa Toloba, Jerome J. Fang, Camilla Pacifici, Raymond Simons, Randy D. Campbell, Daniel Ceverino, Steven L. Finkelstein, Bob Goodrich, Marc Kassis, Anton M. Koekemoer, Nicholas P. Konidaris, Rachel C. Livermore, James E. Lyke, Bahram Mobasher, Hooshang Nayyeri, Michael Peth, Joel R. Primack, Luca Rizzi, Rachel S. Somerville, Gregory D. Wirth, Adi Zolotov
Keck-I Mosfire Spectroscopy Of Compact Star-Forming Galaxies At Z ≳ 2: High Velocity Dispersions In Progenitors Of Compact Quiescent Galaxies, Guillermo Barro, Jonathan R. Trump, David C. Koo, Avishai Dekel, Susan A. Kassin, Dale D. Kocevski, Sandra M. Faber, Arjen Van Der Wel, Yicheng Guo, Pablo G. Pérez-González, Elisa Toloba, Jerome J. Fang, Camilla Pacifici, Raymond Simons, Randy D. Campbell, Daniel Ceverino, Steven L. Finkelstein, Bob Goodrich, Marc Kassis, Anton M. Koekemoer, Nicholas P. Konidaris, Rachel C. Livermore, James E. Lyke, Bahram Mobasher, Hooshang Nayyeri, Michael Peth, Joel R. Primack, Luca Rizzi, Rachel S. Somerville, Gregory D. Wirth, Adi Zolotov
Physics and Astronomy Faculty Publications
We present Keck-I MOSFIRE near-infrared spectroscopy for a sample of 13 compact star-forming galaxies (SFGs) at redshift 2 ≤ z ≤ 2.5 with star formation rates of SFR ~ 100 M ☉ yr–1 and masses of log(M/M ☉) ~10.8. . . .
For the remainder of the abstract, please visit:
http://dx.doi.org/10.1088/0004-637X/795/2/145
The Bulge–Disc Decomposed Evolution Of Massive Galaxies At 1 < Z < 3 In Candels, V. A. Bruce, J. S. Dunlop, R. J. Mclure, M. Cirasuolo, F. Buitrago, R. A. A. Bowler, T. A. Targett, E. F. Bell, D. H. Mcintosh, A. Dekel, S. M. Faber, H. C. Ferguson, N. A. Grogin, W. Hartley, Dale D. Kocevski, A. M. Koekemoer, D. C. Zoo, E. J. Mcgrath
The Bulge–Disc Decomposed Evolution Of Massive Galaxies At 1 < Z < 3 In Candels, V. A. Bruce, J. S. Dunlop, R. J. Mclure, M. Cirasuolo, F. Buitrago, R. A. A. Bowler, T. A. Targett, E. F. Bell, D. H. Mcintosh, A. Dekel, S. M. Faber, H. C. Ferguson, N. A. Grogin, W. Hartley, Dale D. Kocevski, A. M. Koekemoer, D. C. Zoo, E. J. Mcgrath
Physics and Astronomy Faculty Publications
We present the results of a new and improved study of the morphological and spectral evolution of massive galaxies over the redshift range 1 < z < 3. Our analysis is based on a bulge–disc decomposition of 396 galaxies with M* > 1011 M⊙ uncovered from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) Wide Field Camera 3 (WFC3)/IR imaging within the Cosmological Evolution Survey (COSMOS) and UKIRT Infrared Deep Sky Survey (UKIDSS) UDS survey fields. We find that, by modelling the H160 image of each galaxy with a combination of a de Vaucouleurs bulge (Sérsic index n = 4) and an exponential disc (n = 1), we can then …
A Spectroscopic Survey Of Wise -Selected Obscured Quasars With The Southern African Large Telescope, Kevin N. Hainline, Ryan C. Hickox, Christopher M. Carroll, Adam D. Myers
A Spectroscopic Survey Of Wise -Selected Obscured Quasars With The Southern African Large Telescope, Kevin N. Hainline, Ryan C. Hickox, Christopher M. Carroll, Adam D. Myers
Dartmouth Scholarship
We present the results of an optical spectroscopic survey of a sample of 40 candidate obscured quasars identified on the basis of their mid-infrared emission detected by the Wide-Field Infrared Survey Explorer (WISE). Optical spectra for this survey were obtained using the Robert Stobie Spectrograph on the Southern African Large Telescope. Our sample was selected with WISE colors characteristic of active galactic nuclei (AGNs), as well as red optical to mid-IR colors indicating that the optical/UV AGN continuum is obscured by dust. We obtain secure redshifts for the majority of the objects that comprise our sample (35/40), and …
The Decomposed Bulge And Disc Size–Mass Relations Of Massive Galaxies At 1 < Z < 3 In Candels, V. A. Bruce, J. S. Dunlop, R. J. Mclure, M. Cirasuolo, F. Buitrago, R. A. A. Bowler, T. A. Targett, E. F. Bell, D. H. Mcintosh, A. Dekel, S. M. Faber, H. C. Ferguson, N. A. Grogin, W. Hartley, Dale D. Kocevski, A. M. Koekemoer, D. C. Koo, E. J. Mcgrath
The Decomposed Bulge And Disc Size–Mass Relations Of Massive Galaxies At 1 < Z < 3 In Candels, V. A. Bruce, J. S. Dunlop, R. J. Mclure, M. Cirasuolo, F. Buitrago, R. A. A. Bowler, T. A. Targett, E. F. Bell, D. H. Mcintosh, A. Dekel, S. M. Faber, H. C. Ferguson, N. A. Grogin, W. Hartley, Dale D. Kocevski, A. M. Koekemoer, D. C. Koo, E. J. Mcgrath
Physics and Astronomy Faculty Publications
We have constructed a mass-selected sample of M* > 1011 M⊙ galaxies at 1 < z < 3 in the CANDELS UKIDSS UDS and COSMOS fields and have decomposed these systems into their separate bulge and disc components according to their H160-band morphologies. By extending this analysis to multiple bands, we have been able to conduct individual bulge and disc component SED fitting which has provided us with stellar-mass and star formation rate estimates for the separate bulge and disc components. Having utilized the new decomposed stellar-mass estimates, we confirm that the bulge components display a stronger size evolution than the discs. The median sizes of the bulge components is 3.09 ± 0.20 times smaller than similarly massive local galaxies over the …
No More Active Galactic Nuclei In Clumpy Disks Than In Smooth Galaxies At Z ~ 2 In Candels/3d-Hst*, Jonathan R. Trump, Guillermo Barro, Stéphanie Juneau, Benjamin J. Weiner, Bin Luo, Gabriel B. Brammer, Eric F. Bell, W. N. Brandt, Avishai Dekel, Yicheng Guo, Philip F. Hopkins, David C. Koo, Dale D. Kocevski, Daniel H. Mcintosh, Ivelina Momcheva, S. M. Faber, Henry C. Ferguson, Norman A. Grogin, Jeyhan Kartaltepe, Anton M. Koekemoer, Jennifer Lotz, Michael Maseda, Mark Mozena, Kirpal Nandra, David J. Rosario, Gergory R. Zeimann
No More Active Galactic Nuclei In Clumpy Disks Than In Smooth Galaxies At Z ~ 2 In Candels/3d-Hst*, Jonathan R. Trump, Guillermo Barro, Stéphanie Juneau, Benjamin J. Weiner, Bin Luo, Gabriel B. Brammer, Eric F. Bell, W. N. Brandt, Avishai Dekel, Yicheng Guo, Philip F. Hopkins, David C. Koo, Dale D. Kocevski, Daniel H. Mcintosh, Ivelina Momcheva, S. M. Faber, Henry C. Ferguson, Norman A. Grogin, Jeyhan Kartaltepe, Anton M. Koekemoer, Jennifer Lotz, Michael Maseda, Mark Mozena, Kirpal Nandra, David J. Rosario, Gergory R. Zeimann
Physics and Astronomy Faculty Publications
We use CANDELS imaging, 3D-HST spectroscopy, and Chandra X-ray data to investigate if active galactic nuclei (AGNs) are preferentially fueled by violent disk instabilities funneling gas into galaxy centers at 1.3 < z < 2.4. We select galaxies undergoing gravitational instabilities using the number of clumps and degree of patchiness as proxies. The CANDELS visual classification system is used to identify 44 clumpy disk galaxies, along with mass-matched comparison samples of smooth and intermediate morphology galaxies. We note that despite being mass-matched and having similar star formation rates, the smoother galaxies tend to be smaller disks with more prominent bulges compared to the clumpy galaxies. The lack of smooth extended disks is probably a general feature of the z ~ 2 galaxy population, and means we cannot directly compare with the clumpy and smooth extended disks observed at lower redshift. We find that z ~ 2 clumpy galaxies have slightly enhanced AGN fractions selected by integrated line ratios (in the mass-excitation method), but the spatially resolved line ratios indicate this is likely due to extended phenomena rather than nuclear AGNs. Meanwhile, the X-ray data show that …
Star Formation Quenching In High-Redshift Large-Scale Structure: Post-Starburst Galaxies In The Ci 1604 Supercluster At Z ~ 0.9, Po-Feng Wu, Roy R. Gal, Brian C. Lemaux, Dale D. Kocevski, Lori M. Lubin, Nicholas Rumbaugh, Gordon K. Squires
Star Formation Quenching In High-Redshift Large-Scale Structure: Post-Starburst Galaxies In The Ci 1604 Supercluster At Z ~ 0.9, Po-Feng Wu, Roy R. Gal, Brian C. Lemaux, Dale D. Kocevski, Lori M. Lubin, Nicholas Rumbaugh, Gordon K. Squires
Physics and Astronomy Faculty Publications
The Cl 1604 supercluster at z ~ 0.9 is one of the most extensively studied high-redshift large-scale structures, with more than 500 spectroscopically confirmed members. It consists of eight clusters and groups, with members numbering from a dozen to nearly a hundred, providing a broad range of environments for investigating the large-scale environmental effects on galaxy evolution. Here we examine the properties of 48 post-starburst galaxies in Cl 1604, comparing them to other galaxy populations in the same supercluster. Incorporating photometry from ground-based optical and near-infrared imaging, along with Spitzer mid-infrared observations, we derive stellar masses for all Cl 1604 …
Candels+3d-Hst: Compact Sfgs At Z ~ 2-3, The Progenitors Of The First Quiescent Galaxies, G. Barro, S. M. Faber, P. G. Pérez-González, C. Pacifici, J. R. Trump, D. C. Koo, S. Wuyts, Y. Guo, E. Bell, A. Dekel, L. Porter, J. Primack, H. Ferguson, M. L. N. Ashby, K. Caputi, D. Ceverino, D. Croton, G. G. Fazio, M. Giavalisco, L. Hsu, Dalibor D. Kocevski, A. Koekemoer, P. Kurcynski, P. Kollipara, J. Lee, D. H. Mcintosh, E. Mcgrath, C. Moody, R. Somerville, C. Papovich, M. Salvato, P. Santini, T. Tal, A. Van Der Wel, C. C. Williams, S. P. Willner, A. Zolotov
Candels+3d-Hst: Compact Sfgs At Z ~ 2-3, The Progenitors Of The First Quiescent Galaxies, G. Barro, S. M. Faber, P. G. Pérez-González, C. Pacifici, J. R. Trump, D. C. Koo, S. Wuyts, Y. Guo, E. Bell, A. Dekel, L. Porter, J. Primack, H. Ferguson, M. L. N. Ashby, K. Caputi, D. Ceverino, D. Croton, G. G. Fazio, M. Giavalisco, L. Hsu, Dalibor D. Kocevski, A. Koekemoer, P. Kurcynski, P. Kollipara, J. Lee, D. H. Mcintosh, E. Mcgrath, C. Moody, R. Somerville, C. Papovich, M. Salvato, P. Santini, T. Tal, A. Van Der Wel, C. C. Williams, S. P. Willner, A. Zolotov
Physics and Astronomy Faculty Publications
We analyze the star-forming and structural properties of 45 massive (log(M/M ☉) >10) compact star-forming galaxies (SFGs) at 2 < z < 3 to explore whether they are progenitors of compact quiescent galaxies at z ~ 2. The optical/NIR and far-IR Spitzer/Herschel colors indicate that most compact SFGs are heavily obscured. Nearly half (47%) host an X-ray-bright active galactic nucleus (AGN). In contrast, only about 10% of other massive galaxies at that time host AGNs. Compact SFGs have centrally concentrated light profiles and spheroidal morphologies similar to quiescent galaxies and are thus strikingly different from other SFGs, which typically are disk-like and sometimes clumpy or irregular. Most compact …
The Violent Youth Of Bright And Massive Cluster Galaxies And Their Maturation Over 7 Billion Years, B. Ascaso, B. C. Lemaux, L. M. Lubin, R. R. Gal, Dale D. Kocevski, N. Rumbaugh, G. Squires
The Violent Youth Of Bright And Massive Cluster Galaxies And Their Maturation Over 7 Billion Years, B. Ascaso, B. C. Lemaux, L. M. Lubin, R. R. Gal, Dale D. Kocevski, N. Rumbaugh, G. Squires
Physics and Astronomy Faculty Publications
In this study, we investigate the formation and evolution mechanisms of the brightest cluster galaxies (BCGs) over cosmic time. At high redshift (z ∼ 0.9), we selected BCGs and most massive cluster galaxies (MMCGs) from the Cl1604 supercluster and compared them to low-redshift (z ∼ 0.1) counterparts drawn from the MCXC meta-catalogue, supplemented by Sloan Digital Sky Survey imaging and spectroscopy. We observed striking differences in the morphological, colour, spectral, and stellar mass properties of the BCGs/MMCGs in the two samples. High-redshift BCGs/MMCGs were, in many cases, star-forming, late-type galaxies, with blue broad-band colours, properties largely absent amongst …
A Uv To Mid-Ir Study Of Agn Selection, Sun Mi Chung, Christopher S. Kochanek, Roberto Assef, Michael J. I. Brown, Daniel Stern, Buell T. Jannuzi, Anthony H. Gonzalez, Ryan C. Hickox, John Moustakas
A Uv To Mid-Ir Study Of Agn Selection, Sun Mi Chung, Christopher S. Kochanek, Roberto Assef, Michael J. I. Brown, Daniel Stern, Buell T. Jannuzi, Anthony H. Gonzalez, Ryan C. Hickox, John Moustakas
Dartmouth Scholarship
We classify the spectral energy distributions (SEDs) of 431,038 sources in the 9 deg2 Boötes field of the NOAO Deep Wide-Field Survey (NDWFS). There are up to 17 bands of data available per source, including ultraviolet (GALEX), optical (NDWFS), near-IR (NEWFIRM), and mid-infrared (IRAC and MIPS) data, as well as spectroscopic redshifts for ~20,000 objects, primarily from the AGN and Galaxy Evolution Survey. We fit galaxy, active galactic nucleus (AGN), stellar, and brown dwarf templates to the observed SEDs, which yield spectral classes for the Galactic sources and photometric redshifts and galaxy/AGN luminosities for the extragalactic sources. …
Constraints Of The Radio-Loud/Radio-Quiet Dichotomy From The Fundamental Plane, David Garofalo, Matthew I. Kim, Damian J. Christian
Constraints Of The Radio-Loud/Radio-Quiet Dichotomy From The Fundamental Plane, David Garofalo, Matthew I. Kim, Damian J. Christian
Faculty and Research Publications
The Fundamental Plane for black hole activity constitutes a tight correlation between jet power, X-ray luminosity, and black hole mass. Under the assumption that a Blandford–Znajek-type mechanism, which relies on black hole spin, contributes non-negligibly to jet production, the sufficiently small scatter in the Fundamental Plane shows that black hole spin differences of |Δa| ∼ 1 are not typical among the active galactic nuclei population. If – as it seems – radio-loud and radio-quiet objects are both faithful to the Fundamental Plane, models of black hole accretion in which the radio-loud/radio-quiet dichotomy is based on a spin dichotomy of a∼1/a∼0, …
Optical-Faint, Far-Infrared-Bright Herschel Sources In The Candels Fields: Ultra-Luminous Infrared Galaxies At Z > 1 And The Effect Of Source Blending, Haojing Yan, Mauro Stefanon, Zhiyuan Ma, S. P. Willner, Rachel Somerville, Matthew L.N. Ashby, Romeel Davé, Pablo G. Pérez-González, Antonio Cava, Tommy Wiklind, Dale D. Kocevski, Marc Rafelski, Jeyhan Kartaltepe, Asantha Cooray, Anton M. Koekemoer, Norman A. Grogin
Optical-Faint, Far-Infrared-Bright Herschel Sources In The Candels Fields: Ultra-Luminous Infrared Galaxies At Z > 1 And The Effect Of Source Blending, Haojing Yan, Mauro Stefanon, Zhiyuan Ma, S. P. Willner, Rachel Somerville, Matthew L.N. Ashby, Romeel Davé, Pablo G. Pérez-González, Antonio Cava, Tommy Wiklind, Dale D. Kocevski, Marc Rafelski, Jeyhan Kartaltepe, Asantha Cooray, Anton M. Koekemoer, Norman A. Grogin
Physics and Astronomy Faculty Publications
The Herschel very wide field surveys have charted hundreds of square degrees in multiple far-IR (FIR) bands. While the Sloan Digital Sky Survey (SDSS) is currently the best resource for optical counterpart identifications over such wide areas, it does not detect a large number of Herschel FIR sources and leaves their nature undetermined. As a test case, we studied seven "SDSS-invisible," very bright 250 μm sources (S 250 > 55 mJy) in the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey fields where we have a rich multi-wavelength data set. We took a new approach to decompose the FIR sources, using …
The Angular Clustering Of Infrared-Selected Obscured And Unobscured Quasars, M. A. Dipompeo, A. D. Myers, R. C. Hickox, J. E. Geach, K. N. Hainline
The Angular Clustering Of Infrared-Selected Obscured And Unobscured Quasars, M. A. Dipompeo, A. D. Myers, R. C. Hickox, J. E. Geach, K. N. Hainline
Dartmouth Scholarship
Recent studies of luminous infrared-selected active galactic nuclei (AGN) suggest that the reddest, most obscured objects display a higher angular clustering amplitude, and thus reside in higher-mass dark matter halos. This is a direct contradiction to the prediction of the simplest unification-by-orientation models of AGN and quasars. However, clustering measurements depend strongly on the "mask" that removes low-quality data and describes the sky and selection function. We find that applying a robust, conservative mask to WISE-selected quasars yields a weaker but still significant difference in the bias between obscured and unobscured quasars. These findings are consistent with results from previous …
Test Of Models Of The Cosmic Infrared Background With Multiwavelength Observations Of The Blazar 1es 1218+30.4 In 2009, P. T. Reynolds
Test Of Models Of The Cosmic Infrared Background With Multiwavelength Observations Of The Blazar 1es 1218+30.4 In 2009, P. T. Reynolds
Physical Sciences Publications
We present the results of a multi-wavelength campaign targeting the blazar 1ES 1218+30.4 with observations with the 1.3 m McGraw-Hill optical telescope, the Rossi X-ray Timing Explorer (RXTE), the Fermi Gamma-Ray Space Telescope, and the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The RXTE and VERITAS observations were spread over a 13 day period and revealed clear evidence for flux variability, and a strong X-ray and γ-ray flare on 2009 February 26 (MJD 54888). The campaign delivered a well-sampled broadband energy spectrum with simultaneous RXTE and VERITAS very high energy (VHE, >100 GeV) observations, as well as …
Star Formation In The Ngc 5846 Group Of Galaxies, Lucas Viani
Star Formation In The Ngc 5846 Group Of Galaxies, Lucas Viani
Honors Theses
Environmental interactions in groups and clusters of galaxies are thought to alter the evolution of member galaxies. The goal of this research was to analyze gas and star formation properties of galaxies in the NGC 5846 group. A sample of group galaxies was observed at CTIO (Cerro Tololo Inter-American Observatory in Chile) and KPNO (Kitt Peak National Observatory) using broadband red (R) and narrowband hydrogen emission line (Hα) filters. The images were reduced and analyzed to extract star formation rates and distributions. Neutral hydrogen data from the Arecibo Legacy Fast ALFA (ALFALFA) survey were used to measure the cold neutral …
Comparing Stellar Populations Of Galaxies Across The Hubble Sequence: Reduction Of Pisces Near-Infrared Images, Vaishali Parkash
Comparing Stellar Populations Of Galaxies Across The Hubble Sequence: Reduction Of Pisces Near-Infrared Images, Vaishali Parkash
Honors Theses
To better understand the properties of high redshift galaxies and improve models of galaxy formation, we are investigating color radial profiles to study the stellar age, dust and metallicity distribution of galaxies of varying lumi-nosities and morphological types. Current data obtained in the optical and UV have shown that early-type galaxies have a flat color profile, or are bluer at larger radii, while late-type spirals are redder with increasing radius. These trends are believed to be linked with stellar population ages or dust. To break the age-dust degeneracy as well as to avoid the metallicity dependence, we have obtained near-infrared …
Gemini Long-Slit Observations Of Luminous Obscured Quasars: Further Evidence For An Upper Limit On The Size Of The Narrow-Line Region, Kevin N. Hainline, Ryan C. Hickox, Jenny E. Greene, Adam D. Myers
Gemini Long-Slit Observations Of Luminous Obscured Quasars: Further Evidence For An Upper Limit On The Size Of The Narrow-Line Region, Kevin N. Hainline, Ryan C. Hickox, Jenny E. Greene, Adam D. Myers
Dartmouth Scholarship
We examine the spatial extent of the narrow-line regions (NLRs) of a sample of 30 luminous obscured quasars at 0.4 < z < 0.7 observed with spatially resolved Gemini-N GMOS long-slit spectroscopy. Using the [O III] λ5007 emission feature, we estimate the size of the NLR using a cosmology-independent measurement: the radius where the surface brightness falls to 10–15 erg s–1 cm–2 arcsec–2. We then explore the effects of atmospheric seeing on NLR size measurements and conclude that direct measurements of the NLR size from observed profiles are too large by 0.1-0.2 dex on average, as compared to measurements made to best-fit Sérsic or Voigt profiles convolved with the seeing. These data, which span a full order of magnitude in IR luminosity (log (L 8 μm/erg s–1) = 44.4-45.4), …
Investigating Evidence For Different Black Hole Accretion Modes Since Redshift Z ∼ 1, A. Georgakakis, P. G. Pérez-González, N. Fanidakis, M. Salvato, J. Aird, H. Messias, J. M. Lotz, G. Barro, Li-Ting Hsu, K. Nandra, D. Rosario, M. C. Cooper, Dalibor D. Kocevski, J. A. Newman
Investigating Evidence For Different Black Hole Accretion Modes Since Redshift Z ∼ 1, A. Georgakakis, P. G. Pérez-González, N. Fanidakis, M. Salvato, J. Aird, H. Messias, J. M. Lotz, G. Barro, Li-Ting Hsu, K. Nandra, D. Rosario, M. C. Cooper, Dalibor D. Kocevski, J. A. Newman
Physics and Astronomy Faculty Publications
Chandra data in the COSMOS, AEGIS-XD and 4 Ms Chandra Deep Field South are combined with multiwavelength photometry available in those fields to determine the rest-frame U − V versus V − J colours of X-ray AGN hosts in the redshift intervals 0.1 < z < 0.6 (mean z¯=0.40) and 0.6 < z < 1.2 (mean z¯=0.85). This combination of colours provides an effective and least model-dependent means of separating quiescent from star-forming, including dust reddened, galaxies. Morphological information emphasizes differences between AGN populations split by theirU − V versus V − J colours. AGN in quiescent galaxies consist almost exclusively of bulges, while star-forming hosts are equally split between early- and late-type hosts. The position of AGN hosts on the U − V versusV − J diagram is then used to set limits on the accretion density of the …
Lensed Type Ia Supernovae As Probes Of Cluster Mass Models, J Nordin, David Rubin, J Richard, E Rykoff, Greg Aldering, R Amanullah, H Atek, K Barbary, S Deustua, H K. Fakhouri, A S. Fruchter, A Goobar, I Hook, E Y. Hsiao, Xiaosheng Huang, J P. Kneib, C Lidman, J Meyers, S Perlmutter, C Saunders, A L. Spadafora, N Suzuki
Lensed Type Ia Supernovae As Probes Of Cluster Mass Models, J Nordin, David Rubin, J Richard, E Rykoff, Greg Aldering, R Amanullah, H Atek, K Barbary, S Deustua, H K. Fakhouri, A S. Fruchter, A Goobar, I Hook, E Y. Hsiao, Xiaosheng Huang, J P. Kneib, C Lidman, J Meyers, S Perlmutter, C Saunders, A L. Spadafora, N Suzuki
Physics and Astronomy
Using three magnified Type Ia supernovae (SNe Ia) detected behind CLASH (Cluster Lensing and Supernovae with Hubble) clusters, we perform a first pilot study to see whether standardizable candles can be used to calibrate cluster mass maps created from strong lensing observations. Such calibrations will be crucial when next-generation Hubble Space Telescope cluster surveys (e.g. Frontier) provide magnification maps that will, in turn, form the basis for the exploration of the high-redshift Universe. We classify SNe using combined photometric and spectroscopic observations, finding two of the three to be clearly of Type Ia and the third probable. The SNe exhibit …
Massive Compact Galaxies With High-Velocity Outflows: Morphological Analysis And Constraints On Agn Activity, P. H. Sell, C. A. Tremonti, R. C. Hickox, A. M. Diamond-Stanic
Massive Compact Galaxies With High-Velocity Outflows: Morphological Analysis And Constraints On Agn Activity, P. H. Sell, C. A. Tremonti, R. C. Hickox, A. M. Diamond-Stanic
Dartmouth Scholarship
We investigate the process of rapid star formation quenching in a sample of 12 massive galaxies at intermediate redshift (z~0.6) that host high-velocity ionized gas outflows (v>1000 km/s). We conclude that these fast outflows are most likely driven by feedback from star formation rather than active galactic nuclei (AGN). We use multiwavelength survey and targeted observations of the galaxies to assess their star formation, AGN activity, and morphology. Common attributes include diffuse tidal features indicative of recent mergers accompanied by bright, unresolved cores with effective radii less than a few hundred parsecs. The galaxies are extraordinarily compact for their …
Deep Broadband Observations Of The Distant Gamma-Ray Blazar Pks 1424+240, P. T. Reynolds, Et Al
Deep Broadband Observations Of The Distant Gamma-Ray Blazar Pks 1424+240, P. T. Reynolds, Et Al
Physical Sciences Publications
We present deep VERITAS observations of the blazar PKS 1424+240, along with contemporaneous Fermi Large Area Telescope, Swift X-ray Telescope, and Swift UV Optical Telescope data between 2009 February 19 and 2013 June 8. This blazar resides at a redshift of z ≥ 0.6035, displaying a significantly attenuated gamma-ray flux above 100 GeV due to photon absorption via pair-production with the extragalactic background light. We present more than 100 hr of VERITAS observations over three years, a multiwavelength light curve, and the contemporaneous spectral energy distributions. The source shows a higher flux of (2.1 ± 0.3) × 10–7 photons m–2 …
Black Hole Variability And The Star Formation-Active Galactic Nucleus Connection: Do All Star-Forming Galaxies Host An Active Galactic Nucleus?, Ryan C. Hickox, James R. Mullaney, David M. Alexander, Chien-Ting J. Chen, Francesca M. Civano, Andy D. Goulding, Kevin N. Hainline
Black Hole Variability And The Star Formation-Active Galactic Nucleus Connection: Do All Star-Forming Galaxies Host An Active Galactic Nucleus?, Ryan C. Hickox, James R. Mullaney, David M. Alexander, Chien-Ting J. Chen, Francesca M. Civano, Andy D. Goulding, Kevin N. Hainline
Dartmouth Scholarship
We investigate the effect of active galactic nucleus (AGN) variability on the observed connection between star formation and black hole accretion in extragalactic surveys. Recent studies have reported relatively weak correlations between observed AGN luminosities and the properties of AGN hosts, which has been interpreted to imply that there is no direct connection between AGN activity and star formation. However, AGNs may be expected to vary significantly on a wide range of timescales (from hours to Myr) that are far shorter than the typical timescale for star formation (100 Myr). This variability can have important consequences for observed correlations. We …
Cold Gas Dynamics In Hydra-A: Evidence For A Rotating Disc, S. L. Hamer, A. C. Edge, A. M. Swinbank, J. B. R. Oonk, R. Mittal, B. R. Mcnamara, H. R. Russell, M. N. Bremer, F. Combes, A. C. Fabian, N. P. H. Nesvadba, C. P. O'Dea, S. A. Baum, P. Salomé, G. Tremblay, M. Donahue, Gary J. Ferland, C. L. Sarazin
Cold Gas Dynamics In Hydra-A: Evidence For A Rotating Disc, S. L. Hamer, A. C. Edge, A. M. Swinbank, J. B. R. Oonk, R. Mittal, B. R. Mcnamara, H. R. Russell, M. N. Bremer, F. Combes, A. C. Fabian, N. P. H. Nesvadba, C. P. O'Dea, S. A. Baum, P. Salomé, G. Tremblay, M. Donahue, Gary J. Ferland, C. L. Sarazin
Physics and Astronomy Faculty Publications
We present multifrequency observations of the radio galaxy Hydra-A (3C218) located in the core of a massive, X-ray luminous galaxy cluster. Integral field unit spectroscopy is used to trace the kinematics of the ionized and warm molecular hydrogen which are consistent with an ∼5 kpc rotating disc. Broad, double-peaked lines of CO(2–1), [C II] 157 μm and [O I] 63 μm are detected. We estimate the mass of the cold gas within the disc to be Mgas = 2.3 ± 0.3 × 109 M⊙. These observations demonstrate that the complex line profiles found in the cold …