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Title: A 1420 MHz Catalog of Compact Sources in the Northern Galactic Plane

Abstract

We present a catalog of compact sources of radio emission at 1420 MHz in the northern Galactic plane from the Canadian Galactic Plane Survey. The catalog contains 72,758 compact sources with an angular size less than 3′ within the Galactic longitude range 52° <  ℓ  < 192° down to a 5 σ detection level of ∼1.2 mJy. Linear polarization properties are included for 12,368 sources with signals greater than 4 σ{sub QU} in the Canadian Galactic Plane Survey (CGPS) Stokes Q and U images at the position of the total intensity peak. We compare CGPS flux densities with cataloged flux densities in the Northern VLA Sky Survey catalog for 10,897 isolated unresolved sources with CGPS flux density greater than 4 mJy to search for sources that show variable flux density on timescales of several years. We identify 146 candidate variables that exhibit high fractional variations between the two surveys. In addition, we identify 13 candidate transient sources that have CGPS flux density above 10 mJy but are not detected in the Northern VLA Sky Survey.

Authors:
 [1]; ;  [2];  [3]; ; ; ;  [4]
  1. Inter-University Institute for Data Intensive Astronomy, and Department of Astronomy, University of Cape Town Department of Physics, University of the Western Cape (South Africa)
  2. Department of Physics and Astronomy, University of Calgary (Canada)
  3. National Astronomical Observatories, Chinese Academy of Sciences, Beijing Shi (China)
  4. Dominion Radio Astrophysical Observatory, Herzberg Programs in Astronomy and Astrophysics National Research Council of Canada (Canada)
Publication Date:
OSTI Identifier:
22663794
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (Online); Journal Volume: 153; Journal Issue: 3; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CANADA; CATALOGS; COMPARATIVE EVALUATIONS; COSMIC RADIO SOURCES; FLUX DENSITY; IMAGES; MHZ RANGE; MILKY WAY; POLARIZATION; SIGNALS; TRANSIENTS; VARIATIONS

Citation Formats

Taylor, A. R., Leahy, D. A., Sunstrum, C., Tian, W. W., Kothes, R., Landecker, T. L., Ransom, R. R, and Higgs, L. A.. A 1420 MHz Catalog of Compact Sources in the Northern Galactic Plane. United States: N. p., 2017. Web. doi:10.3847/1538-3881/153/3/113.
Taylor, A. R., Leahy, D. A., Sunstrum, C., Tian, W. W., Kothes, R., Landecker, T. L., Ransom, R. R, & Higgs, L. A.. A 1420 MHz Catalog of Compact Sources in the Northern Galactic Plane. United States. doi:10.3847/1538-3881/153/3/113.
Taylor, A. R., Leahy, D. A., Sunstrum, C., Tian, W. W., Kothes, R., Landecker, T. L., Ransom, R. R, and Higgs, L. A.. Wed . "A 1420 MHz Catalog of Compact Sources in the Northern Galactic Plane". United States. doi:10.3847/1538-3881/153/3/113.
@article{osti_22663794,
title = {A 1420 MHz Catalog of Compact Sources in the Northern Galactic Plane},
author = {Taylor, A. R. and Leahy, D. A. and Sunstrum, C. and Tian, W. W. and Kothes, R. and Landecker, T. L. and Ransom, R. R and Higgs, L. A.},
abstractNote = {We present a catalog of compact sources of radio emission at 1420 MHz in the northern Galactic plane from the Canadian Galactic Plane Survey. The catalog contains 72,758 compact sources with an angular size less than 3′ within the Galactic longitude range 52° <  ℓ  < 192° down to a 5 σ detection level of ∼1.2 mJy. Linear polarization properties are included for 12,368 sources with signals greater than 4 σ{sub QU} in the Canadian Galactic Plane Survey (CGPS) Stokes Q and U images at the position of the total intensity peak. We compare CGPS flux densities with cataloged flux densities in the Northern VLA Sky Survey catalog for 10,897 isolated unresolved sources with CGPS flux density greater than 4 mJy to search for sources that show variable flux density on timescales of several years. We identify 146 candidate variables that exhibit high fractional variations between the two surveys. In addition, we identify 13 candidate transient sources that have CGPS flux density above 10 mJy but are not detected in the Northern VLA Sky Survey.},
doi = {10.3847/1538-3881/153/3/113},
journal = {Astronomical Journal (Online)},
number = 3,
volume = 153,
place = {United States},
year = {Wed Mar 01 00:00:00 EST 2017},
month = {Wed Mar 01 00:00:00 EST 2017}
}
  • We present a catalog of compact sources derived from the QUaD Galactic Plane Survey. The survey covers {approx}800 deg{sup 2} of the inner galaxy (|b| < 4{sup 0}) in Stokes I, Q, and U parameters at 100 and 150 GHz, with angular resolutions of 5 and 3.5 arcmin, respectively. Five hundred and twenty-six unique sources are identified in I, of which 239 are spatially matched between frequency bands, with 53 (234) detected at 100 (150) GHz alone; 170 sources are identified as ultracompact H II regions. Approximating the distribution of total intensity source fluxes as a power law, we findmore » a slope of {gamma}{sub S,100} = -1.8 {+-} 0.4 at 100 GHz and {gamma}{sub S,150} = -2.2 {+-} 0.4 at 150 GHz. Similarly, the power-law index of the source two-point angular correlation function is {gamma}{sub {theta},100} = -1.21 {+-} 0.04 and {gamma}{sub {theta},150} = -1.25 {+-} 0.04. The total intensity spectral index distribution peaks at {alpha}{sub I} {approx} 0.25, indicating that dust emission is not the only source of radiation produced by these objects between 100 and 150 GHz; free-free radiation is likely significant in the 100 GHz band. Four sources are detected in polarized intensity P, of which three have matching counterparts in I. Three of the polarized sources lie close to the Galactic center, Sagittarius A*, Sagittarius B2, and the Galactic Radio Arc, while the fourth is RCW 49, a bright H II region. An extended polarized source, undetected by the source extraction algorithm on account of its {approx}0.{sup 0}5 size, is identified visually, and is an isolated example of large-scale polarized emission oriented distinctly from the bulk Galactic dust polarization.« less
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