English
Related papers

Related papers: A Dense Gas Trigger for OH Megamasers

200 papers

We predict the existence and observational signatures of a new class of objects that assembled early, during the first billion years of cosmic time: Obese Black-hole Galaxies (OBGs). OBGs are objects in which the mass of the central black…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Bhaskar Agarwal , Andrew J. Davis , Sadegh Khochfar , Priyamvada Natarajan , James S. Dunlop

Recent millimeter/sub-millimeter facilities have revealed the physical properties of filamentary molecular clouds in relation to high-mass star formation. A uniform survey of the nearest, face-on star-forming galaxy, the Large Magellanic…

(Abridged) Massive stars can determine the evolution of molecular clouds with their strong ultraviolet (UV) radiation fields. Moreover, UV radiation is relevant in setting the thermal gas pressure in star-forming clouds, whose influence can…

We present Expanded Very Large Array and Arecibo observations of two lensed submm galaxies at z~2.5, in order to search for redshifted 22.235 GHz water megamaser emission. Both SMM J14011+0252 and SMM J16359+6612 have multi-wavelength…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Jeff Wagg , Emmanuel Momjian

Optical depths of dense molecular gas are commonly used in Galactic and extragalactic studies to constrain the dense gas mass of the clouds or galaxies. The optical depths are often obtained based on spatially unresolved data, especially in…

Astrophysics of Galaxies · Physics 2023-09-19 Shu Liu , Junzhi Wang , Fei Li , Jingwen Wu , Zhi-Yu Zhang , Di Li , Ningyu Tang , Pei Zuo

We present a study of the stellar host galaxy, CO (1$-$0) molecular gas distribution and AGN emission on 50 to 500 pc-scales of the gravitationally lensed dust-obscured AGN MG J0751+2716 and JVAS B1938+666 at redshifts 3.200 and 2.059,…

This paper addresses the global molecular gas properties of a representative sample of galaxies hosting low-luminosity quasistellar objects. An abundant supply of gas is necessary to fuel both the active galactic nucleus and any…

Astrophysics · Physics 2007-06-20 T. Bertram , A. Eckart , S. Fischer , J. Zuther , C. Straubmeier , L. Wisotzki , M. Krips

Protostellar outflows are considered a signpost of star formation. These outflows can cause shocks in the molecular gas and are typically traced by the line wings of certain molecules. HNCO (4--3) has been regarded as a shock tracer because…

Astrophysics of Galaxies · Physics 2023-06-07 Jinjin Xie , Juan Li , Junzhi Wang , Shu Liu , Kai Yang , Donghui Quan , Siqi Zheng , Yuqiang Li , Jingwen Wu , Yan Duan , Di Li

Extragalactic water maser emissions at 22 GHz have been playing vital roles in astrophysics. The limited detection rate of these masers has been motivating researchers to find clues that can help characterise them. The physical environments…

Astrophysics of Galaxies · Physics 2023-03-15 A. Farhan , E. N. Ercan , F. Tombesi

Long-duration gamma-ray bursts are associated with the explosions of massive stars and are accordingly expected to reside in star-forming regions with molecular gas (the fuel for star formation). Previous searches for carbon monoxide (CO),…

Astrophysics of Galaxies · Physics 2015-06-19 B. Hatsukade , K. Ohta , A. Endo , K. Nakanishi , Y. Tamura , T. Hashimoto , K. Kohno

We present the analysis of a survey of atomic and molecular gas in interacting and merging galaxies (Horellou & Booth 1997). The sample is optically selected and contains all interacting galaxies (~ 60 systems) in a well-defined region of…

Astrophysics · Physics 2009-10-31 Cathy Horellou , Roy Booth , Bruno Karlsson

Investigating star formation requires precise knowledge of the properties of the dense molecular gas. The low metallicity and wide range of star formation activity of the Large and Small Magellanic Clouds make them prime laboratories to…

We present the serendipitous detection of the two main OH maser lines at 1667 and 1665 MHz associated with IRAS 10597+5926 at z = 0.19612 in the untargeted Apertif Wide-area Extragalactic Survey (AWES), and the subsequent measurement of the…

There is growing evidence that the properties of the molecular gas in the nuclei of starburst galaxies and in AGN may be very different from those seen in Galactic star forming regions and that a high kinetic temperature in the molecular…

Astrophysics of Galaxies · Physics 2009-04-14 S. Mühle , E. R. Seaquist , C. Henkel

The hydroxyl radical (OH) is present in the diffuse molecular and partially atomic phases of the interstellar medium (ISM), but its abundance relative to hydrogen is not clear. We aim to evaluate the abundance of OH with respect to…

A ring of dense molecular gas extending 2-7 pc orbits the supermassive black hole Sgr A* at the center of our Galaxy. Using the Green Bank Telescope, we detected water maser lines and both narrow (0.35 km/s) and broad (30 - 50 km/s)…

Astrophysics · Physics 2009-11-13 F. Yusef-Zadeh , J. Braatz , M. Wardle , D. Roberts

Galactic-scale outflows of molecular gas from star-forming galaxies constitute the most direct evidence for regulation of star formation. In the early universe ($ z > 4 $), such outflows have recently been inferred from…

Astrophysics of Galaxies · Physics 2024-03-20 James Nianias , Jeremy Lim , Michael Yeung

We use the IRAM HERACLES survey to study CO emission from 33 nearby spiral galaxies down to very low intensities. Using atomic hydrogen (HI) data, mostly from THINGS, we predict the local mean CO velocity from the mean HI velocity. By…

The clumpy density structure of photon-dominated regions is well established, but the physical properties of the clumps and of the surrounding interclump medium are only approximately known. The aim of this paper is to constrain the…

Astrophysics of Galaxies · Physics 2015-06-03 F. F. S. van der Tak , V. Ossenkopf , Z. Nagy , A. Faure , M. Roellig , E. A. Bergin

The molecular gas in galaxies traces both the fuel for star formation and the processes that can enhance or suppress star formation. Observations of the molecular gas state can thus point to when and why galaxies stop forming stars. In this…