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Related papers: Molecular absorption and its time variations in Ce…

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ALMA cycle 3 observations of $^{12}$CO $ J = 3\rightarrow2$, $^{13}$CO $J = 4\rightarrow 3$, SiO J = $8 \rightarrow 7$, and HCN J = $ 5 \rightarrow 4$ are presented. Significant extended emission is detected in $^{12}$CO J $ =…

Astrophysics of Galaxies · Physics 2020-06-17 Jordan Wheeler , Jason Glenn , Naseem Rangwala , Adalyn Fyhrie

We observed one transit of the extrasolar planet HD 209458b with the NIRSPEC spectrograph on the Keck II telescope. Using time series of low-noise observations in the wavelength range 2.0 micron to 2.5 micron, we searched for extra…

Astrophysics · Physics 2009-11-07 Timothy M. Brown , Kenneth G. Libbrecht , David Charbonneau

We present spatially resolved ($\sim$50 pc) imaging of molecular gas species in the central kiloparsec of the nearby starburst galaxy NGC 253, based on observations taken with the Atacama Large Millimeter/submillimeter Array (ALMA). A total…

In this study, we analyzed millimeter-wave data toward the quasar PKS1830-211 observed with the Atacama Large Millimeter/submillimeter Array to obtain absorption spectra of HCN $J$=2-1, $J$=3-2, $J$=4-3, and $J$=5-4 lines at the…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-26 Tatsuya Kotani , Tomoharu Oka , Rei Enokiya , Kazuki Yanagihara , Miyuki Kaneko , Ryo Ariyama

We present a survey of the Perseus molecular cloud in the J $=$ 1$\rightarrow$0 transition of HCN, a widely used tracer of dense molecular gas. The survey was conducted with the CfA 1.2 m telescope, which at 89 GHz has a beam width of 11'…

Astrophysics of Galaxies · Physics 2023-03-08 T. M. Dame , Charles J. Lada

We report deep K-band (18-27GHz) observations with the 100-m Green Bank Telescope of HCN(1-0) line emission towards the two submillimeter-selected galaxies (SMGs) SMMJ02399-0136 (z=2.81) and SMMJ16359+6612 (z=2.52). For both sources we have…

Astrophysics · Physics 2016-08-15 T. R. Greve , L. J. Hainline , A. W. Blain , Ian Smail , R. J. Ivison , P. P. Papadopoulos

Strong constraints on possible variations in fundamental constants can be derived from HI 21-cm and molecular rotational absorption lines observed towards quasars. With the aim of forming a statistical sample of constraints we have begun a…

Astrophysics · Physics 2016-08-16 S. J. Curran , J. K. Webb , M. T. Murphy , Y. M. Pihlström

Aims. We have searched for temporal variations of narrow absorption lines in high resolution quasar spectra. A sample of 5 distant sources have been assembled, for which 2 spectra - VLT/UVES or Keck/HIRES - taken several years apart are…

Astrophysics of Galaxies · Physics 2015-09-23 P. Boissé , J. Bergeron , J. X. Prochaska , C. Péroux , D. G. York

We searched for shocked carbon chain chemistry (SCCC) sources with C$_3$S abundances surpassing those of HC$_5$N towards the dark cloud L1251, using the Effelsberg telescope at K-band (18 -- 26\,GHz). L1251-1 and L1251-3 are identified as…

We present the results of high spatial resolution observations at 1.1 mm waveband, with the Submillimetre Array (SMA), towards the protocluster G10.6-0.4. The 1.1 mm continuum emission reveals seven dense cores, towards which infall motions…

Solar and Stellar Astrophysics · Physics 2015-06-12 Tie Liu , Yuefang Wu , Jingwen Wu , Sheng-Li Qin , Huawei Zhang

We present here the first results from a high-resolution survey of the 12CO(J=1-0) emission across the northern part of the poorly-enriched Small Magellanic Cloud, made with the ATNF Mopra telescope. Three molecular complexes detected in…

Astrophysics of Galaxies · Physics 2015-05-18 E. Muller , J. Ott , A. Hughes , J. Pineda , T. Wong , N. Mizuno , A. Kawamura , Y. Mizuno , Y. Fukui , T. Onishi , M. Rubio

We present the results of HI and OH absorption measurements towards a sample of radio sources using the Arecibo 305-m telescope and the GMRT. In total, 27 radio sources were searched for associated 21-cm HI absorption. One totally new HI…

Astrophysics · Physics 2009-11-11 Neeraj Gupta , C. J. Salter , D. J. Saikia , T. Ghosh , S. Jeyakumar

Recent studies have shown that both 21cm HI absorption and soft X-ray absorption serve as excellent tracers of the dense and dusty gas near the active nucleus of young radio galaxies, offering new insight into the physical nature of the…

Astrophysics of Galaxies · Physics 2022-01-05 Emily F. Kerrison , Vanessa A. Moss , Elaine M. Sadler , James R. Allison

We report the results of molecular line observations toward the l=1.3 deg complex, ananomalous cloud complex in the central molecular zone of the Galaxy. We have taken high resolution maps of the CO J=1-0, HCN J=1-0, HCO+ J=1-0, SiO J=1-0…

Astrophysics · Physics 2007-05-23 Kunihiko Tanaka , Kazuhisa Kamegai , Makoto Nagai , Tomoharu Oka

I present the first molecular line survey of the strongly lensed submillimetre galaxy SPT-S J002706-5007.4 ($z = 3.44$) using the new Atacama Large Millimeter/submillimeter Array (ALMA) Band~2 receivers (67 - 116 GHz), whose commissioning…

Astrophysics of Galaxies · Physics 2026-05-18 Tom J. L. C. Bakx

We present ALMA observations of the dwarf starburst galaxy Henize 2-10 in combination with previous SMA CO observations to probe the molecular environments of natal super star clusters. These observations include the HCO$^+$(1-0), HCN(1-0),…

Context: We investigated the molecular gas associated with 6.7 GHz methanol masers throughout the Galaxy using a J=1-0 transition of the CO isotopologues. Methods:Using the 13.7-meter telescope at the Purple Mountain Observatory (PMO), we…

Solar and Stellar Astrophysics · Physics 2014-09-05 Zhiyuan Ren , Yuefang Wu , Tie Liu , Lixin Li , Di Li , Binggang Ju

Cen A hosts the closest active galactic nucleus to the Milky Way, which makes it an ideal target for investigating the dynamical processes in the vicinity of accreting supermassive black holes. In this paper, we present 14 Chandra HETGS…

High critical density molecular lines like HCN(1-0) or HCO+(1-0) represent our best tool to study currently star-forming, dense molecular gas at extragalactic distances. The optical depth of these lines is a key ingredient to estimate the…