Showing 2013 · astro-ph.GAShow all

96 papers · 2 filters

astro-ph.GA2013

Flickering of 1.3 cm Sources in Sgr B2: Towards a Solution to the Ultracompact HII Region Lifetime Problem

C. G. De Pree, T. Peters, M. -M. Mac Low +6

Accretion flows onto massive stars must transfer mass so quickly that they are themselves gravitationally unstable, forming dense clumps and filaments. These density perturbations…

astro-ph.GA2013★ 23 cited

The water abundance behind interstellar shocks: results from /PACS and /IRS observations of HO, CO, and H

David A. Neufeld, Antoine Gusdorf, Rolf Güsten +7

We have investigated the water abundance in shock-heated molecular gas, making use of measurements of far-infrared CO and HO line emissions in combination with $Spit…

astro-ph.GA2013★ 99 cited

Indirect ultraviolet photodesorption from CO:N2 binary ices - an efficient grain-gas process

Mathieu Bertin, Edith C. Fayolle, Claire Romanzin +7

UV ice photodesorption is an important non-thermal desorption pathway in many interstellar environments that has been invoked to explain observations of cold molecules in disks, cl…

astro-ph.GA2013★ 158 cited

Parallaxes for W49N and G048.60+0.02: Distant Star Forming Regions in the Perseus Spiral Arm

B. Zhang, M. J. Reid, K. M. Menten +4

We report trigonometric parallax measurements of 22 GHz HO masers in two massive star-forming regions from VLBA observations as part of the BeSSeL Survey. The distances of $11.…

astro-ph.GA2013★ 127 cited

The Parallax of W43: a Massive Star Forming Complex near the Galactic Bar

B. Zhang, L. Moscadelli, M. Sato +7

We report trigonometric parallax measurements of masers in the massive star forming complex W43 from VLBA observations as part of the BeSSeL Survey. Based on measurements of three…

astro-ph.GA2013★ 82 cited

Phosphorus in the Young Supernova Remnant Cassiopeia A

Bon-Chul Koo, Yong-Hyun Lee, Dae-Sik Moon +2

Phosphorus (P), which is essential for life, is thought to be synthesized in massive stars and dispersed into interstellar space when these stars explode as supernovae (SNe)…

astro-ph.GA2013★ 97 cited

Trigonometric parallaxes to star-forming regions within 4 kpc of the galactic center

A. Sanna, M. J. Reid, K. M. Menten +6

We report four trigonometric parallaxes for high-mass star-forming regions within 4 kpc of the Galactic center. These measurements were made with the VLBA as part of the BeSSeL Sur…

astro-ph.GA2013★ 15 cited

Near-infrared counterparts to the Galactic Bulge Survey X-ray source population

S. Greiss, D. Steeghs, P. G. Jonker +6

We report on the near-infrared matches, drawn from three surveys, to the 1640 unique X-ray sources detected by Chandra in the Galactic Bulge Survey (GBS). This survey targets faint…

astro-ph.GA2013★ 36 cited

First hard X-ray detection of the non-thermal emission around the Arches cluster: morphology and spectral studies with NuSTAR

Roman A. Krivonos, John A. Tomsick, Franz E. Bauer +15

The Arches cluster is a young, densely packed massive star cluster in our Galaxy that shows a high level of star formation activity. The nature of the extended non-thermal X-ray em…

astro-ph.GA2013★ 7 cited

The variable ionized absorber in the Seyfert 2 Mrk 348

E. Marchese, V. Braito, J. N Reeves +6

We present the results of the analysis of the X-ray spectrum of the Seyfert 2 Mrk 348, observed by Suzaku and XMM-Newton. The overall spectrum of Mrk 348 can be described by a prim…

astro-ph.GA2013★ 5 cited

Nonthermal Filamentary Radio Features Within 20 pc of the Galactic Center

Mark Morris, Jun-Hui Zhao, W. M. Goss

Deep imaging of the Sgr A complex at 6 cm wavelength with the B and C configurations of the Karl G. Jansky VLA has revealed a new population of faint radio filaments. Like their br…

astro-ph.GA2013★ 13 cited

The M4 Core Project with HST --- I. Overview and First-Epoch

L. R. Bedin, J. Anderson, D. C. Heggie +14

We present an overview of the ongoing Hubble Space Telescope large program GO-12911. The program is focused on the core of M4, the nearest Galactic globular cluster, and the observ…

astro-ph.GA2013★ 14 cited

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 +11

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 resourc…

astro-ph.GA2013★ 25 cited

Supernova Remnant Kes 17: Efficient Cosmic Ray Accelerator inside a Molecular Cloud

Joseph D. Gelfand, Daniel Castro, Patrick O. Slane +3

Supernova remnant Kes 17 (SNR G304.6+0.1) is one of a few but growing number of remnants detected across the electromagnetic spectrum. In this paper, we analyze recent radio, X-ray…

astro-ph.GA2013★ 7 cited

The Dynamics of Ultracompact HII Regions

Nathaniel Roth, Steven W. Stahler, Eric Keto

Many ultracompact HII regions exhibit a cometary morphology in radio continuum emission. In such regions, a young massive star is probably ablating, through its ultraviolet radiati…

astro-ph.GA2013★ 1 cited

A New Perspective on the Radio Active Zone at The Galactic Center - Feedback from Nuclear Activities

Jun-Hui Zhao, Mark R. Morris, W. M. Goss

Based on our deep image of Sgr A using broadband data observed with the Jansky VLA at 6 cm, we present a new perspective of the radio bright zone at the Galactic center. We further…

astro-ph.GA2013★ 67 cited

A survey for transients and variables with the Murchison Widefield Array 32-tile prototype at 154 MHz

M. E. Bell, T. Murphy, D. L. Kaplan +55

We present a search for transient and variable radio sources at 154 MHz with the Murchison Widefield Array 32-tile prototype. Fifty-one images were obtained that cover a field of v…

astro-ph.GA2013★ 23 cited

Towards a better understanding of the distance scale from RR Lyrae variable stars: A case study for the inner halo globular cluster NGC 6723

Jae-Woo Lee, Mercedes Lopez-Morales, Kyeong-Soo Hong +3

We present BV photometry for 54 variables in the metal-rich inner halo globular cluster NGC6723. With the discovery of new RR Lyrae variables (RRLs), we obtain <P_ab> = 0.541 +/- 0…

astro-ph.GA2013★ 6 cited

Multi-epoch VLBA HO maser observations toward the massive YSOs AFGL 2591 VLA 2 and VLA 3

J. M. Torrelles, M. A. Trinidad, S. Curiel +8

We present multi-epoch Very Long Baseline Array (VLBA) HO maser observations toward the massive young stellar objects (YSOs) VLA 2 and VLA 3 in the star-forming region AFGL 259…

astro-ph.GA2013★ 32 cited

The effects of irradiation on the cloud evolution in active galactic nuclei

Daniel Proga, Yan-Fei Jiang, James Stone +2

We report on the first phase of our study of cloud irradiation. We study irradiation by means of numerical, two-dimensional time-dependent radiation-hydrodynamic simulations of a c…

astro-ph.GA2013★ 47 cited

From Poloidal to Toroidal: Detection of Well-ordered Magnetic Field in High-mass Proto-cluster G35.2-0.74N

Keping Qiu, Qizhou Zhang, Karl M. Menten +2

We report on detection of an ordered magnetic field (B field) threading a massive star-forming clump in the molecular cloud G35.2-0.74, using Submillimeter Array observations of po…

astro-ph.GA2013★ 30 cited

Absolutely calibrated radio polarimetry of the inner Galaxy at 2.3 GHz and 4.8 GHz

X. H. Sun, B. M. Gaensler, E. Carretti +4

We present high sensitivity and absolutely calibrated images of diffuse radio polarisation at a resolution of about 10 arcmin covering the range 10 degr <l<34 degr and |b|<5 degr a…

astro-ph.GA2013★ 142 cited

DYNAMO I: A Sample of Ha-Luminous Galaxies with Resolved Kinematics

Andrew W. Green, Karl Glazebrook, Peter J. McGregor +8

(abridged) DYNAMO is a multi-wavelength, spatially-resolved survey of local () star-forming galaxies designed to study evolution through comparison with samples at z~2.…

astro-ph.GA2013★ 56 cited

VLA and CARMA Observations of Protostars in the Cepheus Clouds: Sub-arcsecond Proto-Binaries Formed via Disk Fragmentation

John J. Tobin, Claire J. Chandler, David J. Wilner +8

We present observations of three Class 0/I protostars (L1157-mm, CB230 IRS1, and L1165-SMM1) using the Karl G. Jansky Very Large Array (VLA) and observations of two (L1165-SMM1 and…