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Observations of dense molecular gas lie at the basis of our understanding of the density and temperature structure of protostellar envelopes and molecular outflows. We aim to characterize the properties of the protostellar envelope,…

Solar and Stellar Astrophysics · Physics 2015-05-14 T. A. van Kempen , E. F. van Dishoeck , M. R. Hogerheijde , R. Guesten

The present survey represents a continuation of our study of high mass star forming regions in the lines of deuterated molecules, the first results of which were published in Trofimova et al. (2020). This paper presents the results of…

Astrophysics of Galaxies · Physics 2024-09-17 E. Trofimova , I. Zinchenko , P. Zemlyanukha , M. Thomasson

The deuteration of molecules forming in the ices such as methanol (CH$_3$OH) is sensitive to the physical conditions during their formation in dense cold clouds and can be probed through observations of deuterated methanol in hot cores.…

Absorption lines of H$_2$ and HD molecules observed at high redshift in the line of sight towards quasars are a test ground to search for variation of the proton-to-electron mass ratio $\mu$. For this purpose, results from astronomical…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-13 W. Ubachs , E. J. Salumbides , M. T. Murphy , H. Abgrall , E. Roueff

We measure the band strengths in the far-infrared region of interstellar ice analogs of astrophysically relevant species, such as H$_2$O, CO$_2$, CH$_3$OH, and NH$_3$, deposited at low temperature (8-10 $\mathrm{K}$), followed by warm-up,…

Instrumentation and Methods for Astrophysics · Physics 2014-07-01 B. M. Giuliano , R. M. Escribano , R. Martín-Doménech , E. Dartois , G. M. Muñoz Caro

For a general understanding of the physics involved in the star formation process, measurements of physical parameters such as temperature and density are indispensable. The chemical and physical properties of dense clumps of molecular…

Astrophysics of Galaxies · Physics 2017-02-01 X. D. Tang , C. Henkel , K. M. Menten , X. W. Zheng , J. Esimbek , J. J. Zhou , C. C. Yeh , C. König , Y. Yuan , Y. X. He , D. L. Li

(Abridged) Resolved observations of the CO emission from $z=1-3$ star-forming galaxies are becoming increasingly common, with new high-resolution surveys on the horizon. We aim to inform the interpretation of this resolved CO emission by…

Far-infrared molecular emission is an important tool used to understand the excitation mechanisms of the gas in the inter-stellar medium of star-forming galaxies. In the present work, we model the emission from rotational transitions with…

Astrophysics of Galaxies · Physics 2016-11-23 M. V. Kazandjian , I. Pelupessy , R. Meijerink , F. P. Israel , C. M. Coppola , M. J. F. Rosenberg , M. Spaans

Context: An unexpectedly complex polyatomic chemistry exists in diffuse clouds, allowing detection of species such as C2H, C3H2, H2CO and NH3 which have relative abundances that are strikingly similar to those inferred toward the dark cloud…

Astrophysics of Galaxies · Physics 2009-01-21 H. S. Liszt , J. Pety , R. Lucas

We have mapped the CO(3-2) line emission from several nearby galaxies, using the Heinrich-Hertz-Telescope. Our investigation includes twelve galaxies of various types and in different stages of star forming activity. The main results of…

Astrophysics · Physics 2016-08-30 M. Dumke , Ch. Nieten , G. Thuma , R. Wielebinski , W. Walsh

We present the 3 mm wavelength spectra of 28 local galaxy merger remnants obtained with the Large Millimeter Telescope. Fifteen molecular lines from 13 different molecular species and isotopologues were identified, and 21 out of 28 sources…

Pre-stellar cores are the basic unit for the formation of stars and stellar systems. The anatomy of the physical and chemical structures of pre-stellar cores is critical for understanding the star formation process. L1544 is a prototypical…

Astrophysics of Galaxies · Physics 2022-09-21 Yuxin Lin , Silvia Spezzano , Olli Sipilä , Anton Vasyunin , Paola Caselli

With a goal toward deriving the physical conditions in external galaxies, we present a survey of the formaldehyde emission in a sample of starburst systems. By extending a technique used to derive the spatial density in star formation…

Astrophysics · Physics 2009-11-13 Jeffrey G. Mangum , Jeremy Darling , Karl M. Menten , Christian Henkel

We mapped the kinetic temperature structure of the Orion molecular cloud 1 with para-H2CO(303-202, 322-221, and 321-220) using the APEX 12m telescope. This is compared with the temperatures derived from the ratio of the NH3(2,2)/(1,1)…

Astrophysics of Galaxies · Physics 2017-12-27 X. D. Tang , C. Henkel , K. M. Menten , F. Wyrowski , N. Brinkmann , X. W. Zheng , Y. Gong , Y. X. Lin , J. Esimbek , J. J. Zhou , Y. Yuan , D. L. Li , Y. X. He

Tracing dust in small dense molecular cores is a powerful tool to study the conditions required for ices to form during the pre-stellar phase. To study these environments, five molecular cores were observed: three with ongoing low-mass star…

Astrophysics of Galaxies · Physics 2021-09-08 Laurie E. U. Chu , Klaus W. Hodapp

Massive stars play an important role in the Universe. Unlike low-mass stars, the formation of these objects located at great distances is still unclear. It is expected to be governed by some combination of self-gravity, turbulence, and…

Astrophysics of Galaxies · Physics 2024-12-30 A. G. Pazukhin , I. I. Zinchenko , E. A. Trofimova

NH3 and CH3OH are key molecules in astrochemical networks leading to the formation of more complex N- and O-bearing molecules, such as CH3CN and HCOOCH3. Despite a number of recent studies, little is known about their abundances in the…

We use UV measurements of interstellar CO towards nearby stars to calculate the density in the diffuse molecular clouds containing the molecules responsible for the observed absorption. Chemical models and recent calculations of the…

Astrophysics of Galaxies · Physics 2015-06-16 Paul F. Goldsmith

We determine the gas-phase oxygen abundance for a sample of 695 galaxies and H II regions with reliable detections of [O III]4363, using the temperature-sensitive Te method. Our aims are to estimate the validity of empirical methods such as…

Astrophysics · Physics 2009-11-11 S. Y. Yin , Y. C. Liang , F. Hammer , J. Brinchmann , B. Zhang , L. C. Deng , H. Flores

The outflowing molecular gas in the circumnuclear disk (CND) of the nearby (D=14 Mpc) AGN-starburst composite galaxy NGC 1068 is considered as a manifestation of ongoing AGN feedback. The large spread of velocities from the outflowing gas…

Astrophysics of Galaxies · Physics 2024-04-16 K. -Y. Huang , D. Abbink , S. Viti , S. García-Burillo