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Previous radio recombination line (RRL) observations of dust clumps identified in the APEX Telescope Large Area Survey of the Galaxy (ATLASGAL) have led to the detection of a large number of RRLs in the 3mm range. Here, we aim to study…

Astrophysics of Galaxies · Physics 2018-08-29 W. -J. Kim , J. S. Urquhart , F. Wyrowski , K. M. Menten , T. Csengeri

Based on high quality observations of multiplet V1 of OII and the NLTE atomic computations of OII we study the density and temperature of a sample of HII regions. We find that the signature for oxygen rich clumps of high density and low…

Astrophysics of Galaxies · Physics 2015-06-17 Antonio Peimbert , Manuel Peimbert

We present 10um-35um Spitzer spectra of the interstellar medium in the Central Molecular Zone (CMZ), the central 210 pc x 60 pc of the Galactic center (GC). We present maps of the CMZ in ionic and H2 emission, covering a more extensive area…

Astrophysics of Galaxies · Physics 2015-06-15 Deokkeun An , Solange V. Ramírez , Kris Sellgren

We present spectral line mapping observations toward four massive star-forming regions (Cepheus A, DR21S, S76E and G34.26+0.15), with the IRAM 30 meter telescope at 2 mm and 3 mm bands. Totally 396 spectral lines from 51 molecules, one…

Astrophysics of Galaxies · Physics 2017-01-18 Shanghuo Li , Junzhi Wang , Zhi-Yu Zhang , Min Fang , Juan Li , Jiang- shui Zhang , Junhui Fan , Qingfeng Zhu , Fei Li

Sub-millimeter emission lines produced by the interstellar medium (ISM) are strong tracers of star formation and are some of the main targets of line intensity mapping (LIM) surveys. In this work we present an empirical multi-line emission…

To investigate the interstellar medium (ISM) and Galactic cosmic rays (CRs) in the solar neighborhood, we analyzed ${\gamma}$-ray data by Fermi Large Area Telescope (LAT) for five nearby molecular cloud regions. Our data includes the…

High Energy Astrophysical Phenomena · Physics 2025-06-23 Tsunefumi Mizuno , Katsuhiro Hayashi , Hinako Ochi , Igor V. Moskalenko , Elena Orlando , Andrew W. Strong

The C I 135.58 line is located in the wavelength range of NASA's Interface Region Imagin Spectrograph (IRIS) small explorer mission. We here study the formation and diagnostic potential of this line by means of non…

Solar and Stellar Astrophysics · Physics 2017-09-06 Hsiao-Hsuan Lin , Mats Carlsson , Jorrit Leenaarts

Recombination line profile shapes are derived for ionized spherical stellar winds at radio wavelengths. It is assumed that the wind is optically thick owing to free-free opacity. Emission lines of arbitrary optical depth are obtained…

Solar and Stellar Astrophysics · Physics 2018-11-07 R Ignace

We present new results of a spectroscopic survey of circumstellar HI in the direction of evolved stars made with the Nancay Radiotelescope. The HI line at 21 cm has been detected in the circumstellar shells of a variety of evolved stars:…

Astrophysics · Physics 2018-05-02 Gerard , Le Bertre

We present the results from arcsecond resolution observations of various line transitions at 1.3 mm toward hypercompact HII region G28.20-0.04N. With the SMA data, we have detected and mapped the transitions in the CH$_{3}$CN, CO,…

Astrophysics · Physics 2009-11-13 Sheng-Li Qin , Maohai Huang , Yuefang Wu , Rui Xue , Sheng Chen

HII regions made of gas ionized by radiations from young massive stars, are widely distributed in the Milky Way. They are tracers for star formation, and their distributions are correlated with the Galactic spiral structure. Radio…

Astrophysics of Galaxies · Physics 2021-11-03 Chuan-Peng Zhang , Jin-Long Xu , Guang-Xing Li , Li-Gang Hou , Nai-Ping Yu , Peng Jiang

Understanding the transition from atomic gas to molecular gas is critical to explain the formation and evolution of molecular clouds. However, the gas phases involved, cold HI and CO-dark molecular gas, are challenging to directly observe…

We present VLT/SINFONI near-infrared (NIR) integral field spectroscopy of six $z \sim 0.2$ Lyman break galaxy "analogs" (LBAs), from which we detect HI, HeI, and [FeII] recombination lines, and multiple H$_2$ ro-vibrational lines in…

Astrophysics of Galaxies · Physics 2019-12-30 John F. Wu , Andrew J. Baker , Timothy M. Heckman , Erin K. S. Hicks , Dieter Lutz , Linda J. Tacconi

Although carbon is, together with oxygen and nitrogen, one of the most important elements in the study of galactic chemical evolution its production sites are still poorly known and have been much debated (see e.g. Gustafsson et al. 1999;…

Astrophysics · Physics 2009-11-11 T. Bensby , S. Feltzing

He II Ly-alpha 304/H-alpha 1640 emission lines are mainly produced by recombination, and their canonical ratio of about 10 may be a sensitive reddening indicator. We obtain the high S/N optical spectra of two quasars and combine them with…

Astrophysics · Physics 2009-10-30 Wei Zheng , Li-Zhi Fang

We have observed seven ultracompact HII regions in hydrogen recombination lines in the millimeter band. Toward four of these regions, there is a high velocity (full width to half maximum 60-80 km/s) component in the line profiles. The high…

Astrophysics · Physics 2008-11-26 D. T. Jaffe , J. Martin-Pintado

We present the results of an extensive observational study of the active star-forming complex W51 that was observed in the J=2-1 transition of the 12CO and 13CO molecules over a 1.25 deg x 1.00 deg region with the University of Arizona…

Astrophysics of Galaxies · Physics 2015-05-19 Miju Kang , John H. Bieging , Craig A. Kulesa , Youngung Lee , Minho Choi , William L. Peters

The atomic CII fine-structure line is one of the brightest lines in a typical star-forming galaxy spectrum with a luminosity ~ 0.1% to 1% of the bolometric luminosity. It is potentially a reliable tracer of the dense gas distribution at…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Yan Gong , Asantha Cooray , Marta Silva , Mario G. Santos , James Bock , C. Matt Bradford , Michael Zemcov

We present VLA measurements of H92alpha radio recombination line emission from an unusual HII region G0.18--0.04, the ``Sickle'', with spatial and spectral resolutions of 27" times 24".9 and 14 km/s, respectively. These observations…

Astrophysics · Physics 2015-06-24 F. Yusef-Zadeh , D. A. Roberts , M. Wardle

We present spectral data cubes of the [CI] 809GHz, 12CO 115GHz, 13CO 110GHz and HI 1.4GHz line emission from an 1 square degree region along the l = 328{\deg} (G328) sightline in the Galactic Plane. Emission arises principally from gas in…