Physical Sciences and Mathematics | Open Access Articles

Dusty Structure Around Type-I Active Galactic Nuclei: Clumpy Torus Narrow-Line Region And Near-Nucleus Hot Dust, Rivay Mor, Hagai Netzer, Moshe Elitzur

Physics and Astronomy Faculty Publications

We fitted Spitzer/IRS ~ 2-35 μm spectra of 26 luminous quasi-stellar objects in an attempt to define the main emission components. Our model has three major components: a clumpy torus, dusty narrow-line region (NLR) clouds, and a blackbody-like dust. The models utilize the clumpy torus of Nenkova et al. and are the first to allow its consistent check in type-I active galactic nuclei (AGNs). Single torus models and combined torus-NLR models fail to fit the spectra of most sources, but three-component models adequately fit the spectra of all sources. We present torus inclination, cloud distribution, covering factor, and …

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A Spectroscopically Confirmed Excess Of 24 Μm Sources In A Super Galaxy Group At Z=0.37: Enhanced Dusty Star Formation Relative To The Cluster And Field Environment, Kim-Vy H. Tran, Amelie Saintonge, John Moustakas, Lei Bai, Anthony H. Gonzalez, Bradford P. Holden, Dennis Zaritsky, Stefan Kautsch

Chemistry and Physics Faculty Articles

To trace how dust-obscured star formation varies with environment, we compare the fraction of 24 μm sources in a super galaxy group to the field and a rich galaxy cluster at z ~ 0.35. We draw on multi-wavelength observations that combine Hubble, Chandra, and Spitzer imaging with extensive optical spectroscopy (>1800 redshifts) to isolate galaxies in each environment and thus ensure a uniform analysis. We focus on the four galaxy groups (σ_1D = 303-580 km s^–1) in supergroup 1120-12 that will merge to form a galaxy cluster comparable in mass to Coma. We find …

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An Aztec 1.1 Mm Survey Of The Goods-N Field - Ii. Multiwavelength Identifications And Redshift Distribution, Edward L. Chapin, Alexandra Pope, Douglas Scott, Itziar Aretxaga, Jason E. Austermann, Ranga Ram Chary, Kristen Coppin, Mark Halpern, David H. Hughes, James D. Lowenthal, Glenn E. Morrison, Thushara A. Perera, Kimberly S. Scott, Grant W. Wilson, Min S. Yun

Astronomy: Faculty Publications

We present results from a multiwavelength study of 29 sources (false detection probabilities cent) from a survey of the Great Observatories Origins Deep Survey-North (GOODS-N) field at 1.1 mm using the Astronomical Thermal Emission Camera (AzTEC). Comparing with existing 850 μm Submillimetre Common-User Bolometer Array (SCUBA) studies in the field, we examine differences in the source populations selected at the two wavelengths. The AzTEC observations uniformly cover the entire survey field to a 1σ depth of ∼1 mJy. Searching deep 1.4 GHz Very Large Array (VLA) and Spitzer 3-24 μm catalogues, we identify robust counterparts for 21 1.1 mm sources, …

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Detections Of Water Ice, Hydrocarbons, And 3.3 ΜM Pah In Z ~ 2 Ulirgs, Anna Sajina, Henrik Spoon, Lin Yan, Masatoshi Imanishi, Dario Fadda, Moshe Elitzur

Physics and Astronomy Faculty Publications

We present the first detections of the 3 μm water ice and 3.4 μm amorphous hydrocarbon (HAC) absorption features in z ~ 2 ULIRGs. These are based on deep rest-frame 2-8 μm Spitzer Infrared Spectrograph spectra of 11 sources selected for their appreciable silicate absorption. The HAC-to-silicate ratio for our z ~ 2 sources is typically higher by a factor of 2-5 than that observed in the Milky Way. This HAC “excess” suggests compact nuclei with steep temperature gradients as opposed to predominantly host obscuration. Beside the above molecular absorption features, we detect the 3.3 μm …

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Aztec Millimetre Survey Of The Cosmos Field - Ii. Source Count Overdensity And Correlations With Large-Scale Structure, J. E. Austermann, I. Aretxaga, D. H. Hughes, Y. Kang, S. Kim, James D. Lowenthal, T. A. Perera, D. B. Sanders, K. S. Scott, N. Scoville, G. W. Wilson, M. S. Yun

Astronomy: Faculty Publications

We report an overdensity of bright submillimetre galaxies (SMGs) in the 0.15 deg AzTEC/COSMOS survey and a spatial correlation between the SMGs and the optical-IR galaxy density at z ≲ 1.1. This portion of the COSMOS field shows a ∼3σ overdensity of robust SMG detections when compared to a background, or 'blank-field', population model that is consistent with SMG surveys of fields with no extragalactic bias. The SMG overdensity is most significant in the number of very bright detections (14 sources with measured fluxes S > 6 mJy), which is entirely incompatible with sample variance within our adopted blank-field number densities …

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Two Bright Submillimeter Galaxies In A Z=4.05 Protocluster In Goods-North, And Accurate Radio-Infrared Photometric Redshifts, E Daddi, H Dannerbauer, D Stern, M Dickinson, G Morrison, D Elbaz, M Giavalisco, C Mancini, A Pope, H Spinrad

Astronomy Department Faculty Publication Series

No abstract provided.

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An Aztec 1.1 Mm Survey Of The Goods-N Field - Ii. Multiwavelength Identifications And Redshift Distribution, El Chapin, A Pope, D Scott, I Aretxaga, Je Austermann, Rr Chary, K Coppin, M Halpern, Dh Hughes, Jd Lowenthal, Ge Morrison, Ta Perera, Ks Scott, Gw Wilson, Min Yun

Astronomy Department Faculty Publication Series

We present results from a multiwavelength study of 29 sources (false detection probabilities <5 per cent) from a survey of the Great Observatories Origins Deep Survey-North (GOODS-N) field at 1.1 mm using the Astronomical Thermal Emission Camera (AzTEC). Comparing with existing 850 μm Submillimetre Common-User Bolometer Array (SCUBA) studies in the field, we examine differences in the source populations selected at the two wavelengths. The AzTEC observations uniformly cover the entire survey field to a 1σ depth of ∼1 mJy. Searching deep 1.4 GHz Very Large Array (VLA) and Spitzer 3–24 μm catalogues, we identify robust counterparts for 21 1.1 mm sources, and tentative associations for the remaining objects. The redshift distribution of AzTEC sources is inferred from available spectroscopic and photometric redshifts. We find a median redshift of z= 2.7, somewhat higher than z= 2.0 for 850 μm selected sources in the same field, and our lowest redshift identification lies at a spectroscopic redshift z= 1.1460. We measure the 850 μm to 1.1 mm colour of our sources and do not find …

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Star-Forming Or Starbursting? The Ultraviolet Conundrum, M Boquien, D Calzetti, R Kennicutt, D Dale, C Engelbracht, Kd Gordon, S Hong, Jc Lee, J Portouw

Astronomy Department Faculty Publication Series

Compared to starburst galaxies, normal star-forming galaxies have been shown to display a much larger dispersion of the dust attenuation at fixed reddening through studies of the IRX-β diagram (the IR/UV ratio "IRX" versus the UV color "β"). To investigate the causes of this larger dispersion and attempt to isolate second parameters, we have used GALEX UV, ground-based optical, and Spitzer infrared imaging of eight nearby galaxies, and examined the properties of individual UV and 24 μm selected star-forming regions. We concentrated on star-forming regions, in order to isolate simpler star formation histories than those that characterize whole galaxies. We …

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The Spitzer Local Volume Legacy: Survey Description And Infrared Photometry, Da Dale, Sa Cohen, Lc Johnson, Md Schuster, D Calzetti, Cw Engelbracht, Ag De Paz, Rc Kennicutt, Jc Lee, A Begum, M Block, Jj Dalcanton, Jg Funes, Kd Gordon, Bd Johnson, Ar Marble, S Sakai, Ed Skillman, L Van Zee, F Walter, Dr Weisz, B Williams, Sy Wu, Y Wu

Astronomy Department Faculty Publication Series

The survey description and the near-, mid-, and far-infrared flux properties are presented for the 258 galaxies in the Local Volume Legacy (LVL). LVL is a Spitzer Space Telescope legacy program that surveys the local universe out to 11 Mpc, built upon a foundation of ultraviolet, Hα, and Hubble Space Telescope imaging from 11HUGS (11 Mpc Hα and Ultraviolet Galaxy Survey) and ANGST (ACS Nearby Galaxy Survey Treasury). LVL covers an unbiased, representative, and statistically robust sample of nearby star-forming galaxies, exploiting the highest extragalactic spatial resolution achievable with Spitzer. As a result of its approximately volume-limited nature, LVL augments …

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Aztec Millimetre Survey Of The Cosmos Field - Ii. Source Count Overdensity And Correlations With Large-Scale Structure, Je Austermann, I Aretxaga, Dh Hughes, Y Kang, S Kim, Jd Lowenthal, Ta Perera, Db Sanders, Ks Scott, N Scoville, Gw Wilson, Min Yun

Astronomy Department Faculty Publication Series

We report an overdensity of bright submillimetre galaxies (SMGs) in the 0.15 deg² AzTEC/COSMOS survey and a spatial correlation between the SMGs and the optical-IR galaxy density at z≲ 1.1. This portion of the COSMOS field shows a ∼3σ overdensity of robust SMG detections when compared to a background, or ‘blank-field’, population model that is consistent with SMG surveys of fields with no extragalactic bias. The SMG overdensity is most significant in the number of very bright detections (14 sources with measured fluxes S_{1.1 mm} > 6 mJy), which is entirely incompatible with sample variance within our adopted …

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Collisional Heating As The Origin Of Filament Emission In Galaxy Clusters, G. J. Ferland, A. C. Fabian, N. A. Hatch, R. M. Johnstone, R. L. Porter, P. A. M. Vanhoof, R. J. R. Williams

Physics and Astronomy Faculty Publications

It has long been known that photoionization, whether by starlight or other sources, has difficulty in accounting for the observed spectra of the optical filaments that often surround central galaxies in large clusters. This paper builds on the first of this series in which we examined whether heating by energetic particles or dissipative magnetohydrodynamic (MHD) wave can account for the observations. The first paper focused on the molecular regions which produce strong H₂ and CO lines. Here we extend the calculations to include atomic and low-ionization regions. Two major improvements to the previous calculations have been made. The model …

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Full-Text Articles in Physical Sciences and Mathematics

Dusty Structure Around Type-I Active Galactic Nuclei: Clumpy Torus Narrow-Line Region And Near-Nucleus Hot Dust, Rivay Mor, Hagai Netzer, Moshe Elitzur

Physics and Astronomy Faculty Publications

A Spectroscopically Confirmed Excess Of 24 Μm Sources In A Super Galaxy Group At Z=0.37: Enhanced Dusty Star Formation Relative To The Cluster And Field Environment, Kim-Vy H. Tran, Amelie Saintonge, John Moustakas, Lei Bai, Anthony H. Gonzalez, Bradford P. Holden, Dennis Zaritsky, Stefan Kautsch

Chemistry and Physics Faculty Articles

Astronomy: Faculty Publications

Detections Of Water Ice, Hydrocarbons, And 3.3 ΜM Pah In Z ~ 2 Ulirgs, Anna Sajina, Henrik Spoon, Lin Yan, Masatoshi Imanishi, Dario Fadda, Moshe Elitzur

Physics and Astronomy Faculty Publications

Aztec Millimetre Survey Of The Cosmos Field - Ii. Source Count Overdensity And Correlations With Large-Scale Structure, J. E. Austermann, I. Aretxaga, D. H. Hughes, Y. Kang, S. Kim, James D. Lowenthal, T. A. Perera, D. B. Sanders, K. S. Scott, N. Scoville, G. W. Wilson, M. S. Yun

Astronomy: Faculty Publications

Two Bright Submillimeter Galaxies In A Z=4.05 Protocluster In Goods-North, And Accurate Radio-Infrared Photometric Redshifts, E Daddi, H Dannerbauer, D Stern, M Dickinson, G Morrison, D Elbaz, M Giavalisco, C Mancini, A Pope, H Spinrad

Astronomy Department Faculty Publication Series

An Aztec 1.1 Mm Survey Of The Goods-N Field - Ii. Multiwavelength Identifications And Redshift Distribution, El Chapin, A Pope, D Scott, I Aretxaga, Je Austermann, Rr Chary, K Coppin, M Halpern, Dh Hughes, Jd Lowenthal, Ge Morrison, Ta Perera, Ks Scott, Gw Wilson, Min Yun

Astronomy Department Faculty Publication Series

Star-Forming Or Starbursting? The Ultraviolet Conundrum, M Boquien, D Calzetti, R Kennicutt, D Dale, C Engelbracht, Kd Gordon, S Hong, Jc Lee, J Portouw

Astronomy Department Faculty Publication Series

Astronomy Department Faculty Publication Series

Aztec Millimetre Survey Of The Cosmos Field - Ii. Source Count Overdensity And Correlations With Large-Scale Structure, Je Austermann, I Aretxaga, Dh Hughes, Y Kang, S Kim, Jd Lowenthal, Ta Perera, Db Sanders, Ks Scott, N Scoville, Gw Wilson, Min Yun

Astronomy Department Faculty Publication Series

Collisional Heating As The Origin Of Filament Emission In Galaxy Clusters, G. J. Ferland, A. C. Fabian, N. A. Hatch, R. M. Johnstone, R. L. Porter, P. A. M. Vanhoof, R. J. R. Williams

Physics and Astronomy Faculty Publications