GLOSTAR: Radio Source Catalog I. 28° <  ℓ < 36° and |b| < 1°

Context. Radio continuum surveys of the Galactic plane are an excellent way to identify different source populations such as planetary nebulae, H II regions, and radio stars and characterize their statistical properties. The Global View of Star Formation in the Milky Way (GLOSTAR) survey will study the star formation in the Galactic plane between −2° < ℓ < 85° and |b| < 1° with unprecedented sensitivity in both flux density (∼40 μJy beam−1) and range ofangular scales (∼1".5 to the largest radio structures in the Galaxy). Aims. In this paper we present the first results obtained from a radio continuum map of a 16-square-degree-sized region of the Galactic plane centered on ℓ = 32° and b = 0° (28° < ℓ < 36° and |b| < 1°). This map has a resolution of 18″ and a sensitivity of ∼60−150 μJy beam−1. Methods. We present data acquired in 40 h of observations with the VLA in D-configuration. Two 1 GHz wide sub-bands were observed simultaneously and they were centered at 4.7 and 6.9 GHz. These data were calibrated and imaged using the Obit software package. The source extraction was performed using the BLOBCAT software package and verified through a combination of visual inspection and cross-matching with other radio and mid-infrared surveys. Results. The final catalog consists of 1575 discrete radio sources and 27 large scale structures (including W43 and W44). By cross-matching with other catalogs and calculating the spectral indices (S(ν) ∝ να), we have classified 231 continuum sources as H II regions, 37 as ionization fronts, and 46 as planetary nebulae. The longitude and latitude distribution and negative spectral indices are all consistent with the vast majority of the unclassified sources being extragalactic background sources. Conclusions. We present a catalog of 1575 radio continuum sources and discuss their physical properties, emission nature, and relation to previously reported data. These first GLOSTAR results have increased the number of reliable H II regions in this part of the Galaxy by a factor of four.

[1]  R. Klessen,et al.  Radio continuum emission in the northern Galactic plane: Sources and spectral indices from the THOR survey (Corrigendum) , 2018, Astronomy & Astrophysics.

[2]  L. Loinard,et al.  The Enigmatic Compact Radio Source Coincident with the Energetic X-Ray Pulsar PSR J1813–1749 and HESS J1813–178 , 2018, The Astrophysical Journal.

[3]  R. Perley,et al.  The Angular Size Distribution of μJy Radio Sources , 2018 .

[4]  A. Zijlstra,et al.  The coordinated radio and infrared survey for high-mass star formation – IV. A new radio-selected sample of compact galactic planetary nebulae , 2018, Monthly Notices of the Royal Astronomical Society.

[5]  R. Perley,et al.  Angular Sizes of $\mu$Jy Radio Sources , 2018, 1802.04209.

[6]  L. Loinard,et al.  Richness of compact radio sources in NGC 6334D to F , 2017, 1711.02934.

[7]  Hertfordshire,et al.  ATLASGAL - properties of a complete sample of Galactic clumps , 2017, 1709.00392.

[8]  S. J. Liu,et al.  The Hi-GAL compact source catalogue – I. The physical properties of the clumps in the inner Galaxy (−71. ◦ 0 < ℓ < 67.◦ 0) , 2017, 1706.01046.

[9]  S. J. Liu,et al.  Properties of Hi-GAL clumps in the inner Galaxy]{The Hi-GAL compact source catalogue. I. The physical properties of the clumps in the inner Galaxy ($-71.0^{\circ}< \ell < 67.0^{\circ}$) , 2017, 1706.01046.

[10]  R. Klessen,et al.  Galactic Supernova Remnant Candidates Discovered by THOR , 2017, 1705.10927.

[11]  A. Ginsburg,et al.  SEDIGISM: Structure, excitation, and dynamics of the inner Galactic interstellar medium , 2017, 1701.04712.

[12]  L. Loinard,et al.  Searching for Compact Radio Sources Associated with UCH ii Regions , 2017, 1701.02717.

[13]  R. Klessen,et al.  The HI/OH/Recombination line survey of the inner Milky Way (THOR). Survey overview and data release 1 , 2016, 1609.03329.

[14]  K. Menten,et al.  A PARALLAX-BASED DISTANCE ESTIMATOR FOR SPIRAL ARM SOURCES , 2016, 1604.02433.

[15]  Ivan Bojicic,et al.  HASH: the Hong Kong/AAO/Strasbourg Hα planetary nebula database , 2016, 1603.07042.

[16]  R. Klessen,et al.  Continuum sources from the THOR survey between 1 and 2 GHz , 2016, 1601.03427.

[17]  R. Klessen,et al.  THOR: The H I, OH, Recombination line survey of the Milky Way. The pilot study: H I observations of the giant molecular cloud W43 , 2015, 1505.05176.

[18]  F. Owen,et al.  THE COMPLEX NORTH TRANSITION REGION OF CENTAURUS A: RADIO STRUCTURE , 2015, 1502.05066.

[19]  D. Jones,et al.  Giant radio galaxies - II. Tracers of large-scale structure , 2015, 1502.03954.

[20]  D. A. Green,et al.  A catalogue of 294 Galactic supernova remnants , 2014, 1409.0637.

[21]  Leiden,et al.  ATLASGAL — towards a complete sample of massive star forming clumps ⋆ , 2014, 1406.5078.

[22]  S. Bontemps,et al.  The ATLASGAL survey: a catalog of dust condensations in the Galactic plane , 2013, 1312.0937.

[23]  S. Bontemps,et al.  ATLASGAL - Complete compact source catalogue: 280 ◦ < < 60 ◦ (Research Note) , 2014 .

[24]  V. Cunningham,et al.  THE WISE CATALOG OF GALACTIC H ii REGIONS , 2013, 1312.6202.

[25]  L. Hartmann,et al.  THE GOULD’S BELT VERY LARGE ARRAY SURVEY. II. THE SERPENS REGION , 2013, 1307.5105.

[26]  Dublin Institute for Advanced Studies,et al.  ATLASGAL - properties of compact H II regions and their natal clumps , 2013, 1307.4105.

[27]  L. Mundy,et al.  THE COORDINATED RADIO AND INFRARED SURVEY FOR HIGH-MASS STAR FORMATION. II. SOURCE CATALOG , 2012, 1211.7116.

[28]  L. Mundy,et al.  The Co-ordinated Radio and Infrared Survey for High-Mass Star Formation-II. Source Catalogue , 2013 .

[29]  S. Bontemps,et al.  ATLASGAL – compact source catalogue: 330° < ℓ < 21° , 2013 .

[30]  L. Mundy,et al.  The Coordinated Radio and Infrared Survey for High-Mass Star Formation (The CORNISH Survey). I. Survey Design , 2012, 1208.3351.

[31]  A. Raga,et al.  COMPACT RADIO SOURCES IN M17 , 2012, 1206.5339.

[32]  James R. Curran,et al.  blobcat: software to catalogue flood‐filled blobs in radio images of total intensity and linear polarization , 2012, 1205.5313.

[33]  S. Bontemps,et al.  GALACTIC STRUCTURE BASED ON THE ATLASGAL 870 μm SURVEY , 2011, 1112.4609.

[34]  M. Sauvage,et al.  The Herschel view of massive star formation in G035.39-00.33: dense and cold filament of W48 undergoing a mini-starburst , 2011, 1109.3584.

[35]  Exeter,et al.  The RMS Survey: Ammonia and water maser analysis of massive star forming regions. ⋆ , 2011, 1107.3913.

[36]  B. J. Butler,et al.  THE EXPANDED VERY LARGE ARRAY: A NEW TELESCOPE FOR NEW SCIENCE , 2011, 1106.0532.

[37]  Jonathan P. Williams,et al.  THE BOLOCAM GALACTIC PLANE SURVEY: SURVEY DESCRIPTION AND DATA REDUCTION , 2010, 1011.0691.

[38]  Martin G. Cohen,et al.  THE WIDE-FIELD INFRARED SURVEY EXPLORER (WISE): MISSION DESCRIPTION AND INITIAL ON-ORBIT PERFORMANCE , 2010, 1008.0031.

[39]  M. Sauvage,et al.  Clouds, filaments, and protostars: TheHerschel Hi-GAL Milky Way , 2010, 1005.3317.

[40]  R. Becker,et al.  VARIABLE RADIO SOURCES IN THE GALACTIC PLANE , 2010, 1005.1572.

[41]  Mubdi Rahman,et al.  Massive Star Forming Regions in the Galaxy using the Spitzer GLIMPSE Survey , 2010, 1004.3290.

[42]  G. Dubner,et al.  A multiwavelength study of the star forming region IRAS 18544+0112 , 2009, 0912.1837.

[43]  A. L. Busfield,et al.  The RMS survey - 6 cm continuum VLA observations towards candidate massive YSOs in the northern hemisphere , 2009, 0905.1174.

[44]  R. Indebetouw,et al.  The Spitzer/GLIMPSE Surveys: A New View of the Milky Way , 2009 .

[45]  A. Weiss,et al.  ATLASGAL - The APEX telescope large area survey of the galaxy at 870 μm , 2009, 0903.1369.

[46]  F. Camilo,et al.  Discovery of 28 pulsars using new techniques for sorting pulsar candidates , 2009, 0901.3570.

[47]  W. Brisken,et al.  PRECISION SOUTHERN HEMISPHERE PULSAR VLBI ASTROMETRY: TECHNIQUES AND RESULTS FOR PSR J1559–4438 , 2008, 0808.1598.

[48]  N. Rodríguez-Fernández,et al.  Gas flow models in the Milky Way embedded bars , 2008, 0806.4252.

[49]  William D. Cotton,et al.  Obit: A Development Environment for Astronomical Algorithms , 2008 .

[50]  A. L. Busfield,et al.  The RMS survey: radio observations of candidate massive YSOs in the southern hemisphere , 2006, Proceedings of the International Astronomical Union.

[51]  T. J. Millar,et al.  A SCUBA imaging survey of ultracompact HII regions. The environments of massive star formation , 2006, astro-ph/0604208.

[52]  R. Becker,et al.  MAGPIS: A Multi-Array Galactic Plane Imaging Survey , 2006 .

[53]  D. Padgett,et al.  MIPSGAL: A Survey of the Inner Galactic Plane at 24 and 70 μm , 2005 .

[54]  P. Hofner,et al.  Water Masers Toward Ultracompact H II Regions , 2005, astro-ph/0507039.

[55]  R. Kennicutt.  The role of massive stars in astrophysics , 2005, Proceedings of the International Astronomical Union.

[56]  R. Becker,et al.  A New Catalog of Radio Compact H II Regions in the Milky Way , 2004, astro-ph/0503425.

[57]  A. Lyne,et al.  Long-term timing observations of 374 pulsars , 2004 .

[58]  R. Norris,et al.  The protostellar mass limit for 6.7 GHz methanol masers. I. A low-mass YSO survey , 2003 .

[59]  B. Garilli,et al.  The VLA-VIRMOS Deep Field I. Radio observations probing the microJy source population , 2003, astro-ph/0303364.

[60]  F. Motte,et al.  From Massive Protostars to a Giant H II Region: Submillimeter Imaging of the Galactic Ministarburst W43 , 2002, astro-ph/0208519.

[61]  J. Leahy,et al.  Spectral Structure in FR II Radio Galaxies and Jets , 2001, astro-ph/0108264.

[62]  W. Goss,et al.  Measurement of the Parallax of PSR B0950+08 Using the VLBA , 2000, astro-ph/0005324.

[63]  R. Norris,et al.  Radio Observations of the Hubble Deep Field-South Region. II. The 1.4 GHz Catalog and Source Counts , 1999, astro-ph/9910437.

[64]  A. Watson,et al.  Ultracompact H II Regions with Extended Radio-Continuum Emission , 1999 .

[65]  P. Conti,et al.  The Stellar Content of Obscured Galactic Giant H II Regions. II. W42 , 1998, astro-ph/0001157.

[66]  R. Blum,et al.  The Stellar Content of Obscured Galactic Giant H II Regions. I. W43 , 1998, astro-ph/9812070.

[67]  E. Bertin,et al.  SExtractor: Software for source extraction , 1996 .

[68]  Robert H. Becker,et al.  A 5-GHz VLA Survey of the Galactic Plane (Becker+ 1994) , 1994 .

[69]  R. Windhorst,et al.  The micro-jansky radio source population at 5 GHz , 1991 .

[70]  F. Lockman,et al.  A Survey of Radio H II Regions in the Northern Sky (Lockman+ 1989) , 1989 .

[71]  G. Garay,et al.  Rotating and Expanding Ultracompact H II Regions , 1986 .

[72]  J. J. Condon.  Cosmological evolution of radio sources , 1984 .

[73]  C. Beichman,et al.  VLA observations of W 33, W 44, and GL 2591 , 1981 .

[74]  J. H. Parkinson,et al.  Transient X-ray sources , 1975, Nature.