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We present molecular line and 1.4 mm continuum observations towards five massive star forming regions at arcsecond resolution using the Submillimeter Array (SMA). We find that the warm molecular gas surrounding each HII region (as traced by…

Solar and Stellar Astrophysics · Physics 2015-05-13 P. D. Klaassen , C. D. Wilson , E. R. Keto , Q. Zhang

Deep optical CCD images of the supernova remnant G 15.1-1.6 were obtained and filamentary and diffuse emission has been discovered. The images, taken in the emission lines of Halpha+[N II], [S II] and [O III], reveal filamentary and diffuse…

We present the first results of a study of the kinematics and morphology of ultracompact HII regions using a new observational technique. We used very high spatial (1.5") and spectral (3.4 km/s)resolution observations of the [NeII] line at…

Astrophysics · Physics 2009-11-10 D. T. Jaffe , Q. Zhu , J. H. Lacy , M. Richter

We present results from a sample of 106 high-luminosity IRAS sources observed with the Very Large Array in the B and C configurations. 96 sources were observed in the X-band and 52 in the K-band, with 42 of them observed at both…

Astrophysics of Galaxies · Physics 2023-06-16 D. Quiroga-Gonzalez , M. A. Trinidad , E. de la Fuente , J. M. Masque , T. Rodriguez-Esnard

We report molecular line and dust continuum observations toward the high-mass star forming region G331.5-0.1, one of the most luminous regions of massive star-formation in the Milky Way, located at the tangent region of the Norma spiral…

Astrophysics of Galaxies · Physics 2015-06-16 Manuel Merello , Leonardo Bronfman , Guido Garay , Lars-Ake Nyman , Neal J. Evans , C. Malcolm Walmsley

High-resolution (R=60000) echelle spectroscopy of the post-AGB supergiant V5112 Sgr performed in 1996-2012 with the 6-m telescope BTA has revealed peculiarities of the star optical spectrum and has allowed the variability of the velocity…

Solar and Stellar Astrophysics · Physics 2015-06-17 V. G. Klochkova.

We report the detection of stimulated hydrogen radio recombination line (RRL) emission from ionized gas in a $z=0.89$ galaxy using 580--1670 MHz observations from the MeerKAT Absorption Line Survey (MALS). The RRL emission originates in a…

Hypercompact HII regions (HC) are regions of ionized gas associated with the early stages of high-mass star formation. With the aim of better understanding their characteristics, we studied five candidate HC HII regions. Here, we present…

Astrophysics of Galaxies · Physics 2026-05-12 I. T. Rodríguez-Esnard , S. Kurtz , J. D. Pandian , J. Franco , A. Sánchez-Monge , M. A. Trinidad , V. Migenes

We observed radio recombination lines (RRLs) toward the W51 molecular cloud complex, one of the most active star forming regions in our Galaxy. The UV radiation from young massive stars ionizes gas surrounding them to produce HII regions.…

Astrophysics of Galaxies · Physics 2019-12-10 Mishaal. I. Jan , D. Anish Roshi , M. E. Lebrón , E. Pacheco , T. Ghosh , C. J. Salter , R. Minchin , E. D. Araya , H. G. Arce

G34.26+0.15 is a region of high-mass star formation that contains a broad range of young stellar objects in different stages of evolution, including a hot molecular core, hyper-compact HII regions and a prototypical cometary ultra-compact…

Astrophysics of Galaxies · Physics 2023-08-16 W. S. Tan , E. D. Araya , C. Rigg , P. Hofner , S. Kurtz , H. Linz , V. Rosero

We propose new diagnostics for circumstellar interaction in Type IIP supernovae by the detection of high velocity (HV) absorption features in Halpha and He I 10830 A lines during the photospheric stage. To demonstrate the method, we compute…

Astrophysics · Physics 2011-02-11 Nikolai N. Chugai , Roger A. Chevalier , Victor P. Utrobin

The Brackett decrement in the Class I source HH100 IR has been observed and analyzed to set constraints on the origin of the IR HI emission in this young object. We have used both low resolution (R ~ 800) observations of the Brackett lines…

Astrophysics · Physics 2009-11-10 Brunella Nisini , Simone Antoniucci , Teresa Giannini

Massive star-forming regions exhibit a rich chemistry with complex gas distributions, especially on small scales. While surveys have yielded constraints on typical gas conditions, they often have coarse spatial resolution and limited…

We probe the structure and kinematics of two neighbouring H II regions identified as cometary and bipolar, using radio recombination lines (RRL). The H172{\alpha} RRLs from these H II regions: G351.6-1.15 and G351.6-1.25, are mapped using…

Astrophysics of Galaxies · Physics 2017-01-11 V. S. Veena , S. Vig , A. Tej , N. G. Kantharia , S. K. Ghosh

Aims. We present a multiwavelength study of two southern Galactic H II regions G346.056-0.021 and G346.077-0.056 which are located at a distance of 10.9 kpc. The distribution of ionized gas, cold and warm dust and the stellar population…

Astrophysics of Galaxies · Physics 2017-11-15 Swagat Ranjan Das , Anandmayee Tej , Sarita Vig , Tie Liu , Swarna K. Ghosh , Ishwara Chandra C. H.

We present and discuss the properties of an ionized component with extreme kinematics in an off-nuclear HII region located at 0.8 - 1.0 kpc from the nucleus of SDSS J143245.98+404300.3, recently reported in Rodriguez del Pino et al. (2019).…

We observed the ultra-compact binary candidate 4U 0614+091 for a total of 200 ksec with the high-energy transmission gratings onboard the \chandra X-ray Observatory. The source is found at various intensity levels with spectral variations…

High Energy Astrophysical Phenomena · Physics 2015-05-18 Norbert S. Schulz , Michael P. Nowak , Deepto Chakrabarty , Claude R. Canizares

(first paragraph) We have obtained Halpha and Palpha emission line images covering the central 3 - 4 arcmin of M51 using the WFPC2 and NICMOS cameras on HST to study the high-mass stellar population. The 0.1 - 0.2 arcsec pixels provide 4.6…

Astrophysics · Physics 2016-08-30 N. Z. Scoville , M. Polletta , S. Ewald , S. R. Stolovy , R. Thompson , M. Rieke

We report new results based on the analysis of the SMA and CARMA observations of NGC 7538\,IRS\,1 at 1.3 and 3.4 mm with sub-arcsec resolutions. With angular resolutions $\sim$ 0\farcs7, the SMA and CARMA observations show that the…

Solar and Stellar Astrophysics · Physics 2019-08-19 Lei Zhu , Jun-Hui Zhao , Melvyn Wright , Göran Sandell , Hui Shi , Yue-Fang Wu , Crystal Brogan , Stuartt Corder

We study the exponential scale length of total radio emission, the spectral index distribution, and the linear radio polarization in the Scd galaxy M33. Observations were carried out using the 3.6 cm dual channel and the 6.2 cm four channel…

Astrophysics · Physics 2009-11-13 F. S. Tabatabaei , M. Krause , R. Beck