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Related papers: Dense Molecular Gas in Lenticular Galaxies

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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…

We present observations of the HCN and HCO+ J=1-0 transitions in the center of the nearby spiral galaxy NGC 6946 made with the BIMA and CARMA interferometers. Using the BIMA SONG CO map, we investigate the change in the I_HCN/I_CO and I_…

Astrophysics · Physics 2009-11-13 E. S. Levine , Tamara T. Helfer , R. Meijerink , Leo Blitz

The star formation rate (SFR) is tightly connected to the amount of dense gas in molecular clouds. However, it is not fully understood how the relationship between dense molecular gas and star formation varies within galaxies and in…

We present a study of dense gas emission in the Milky Way in order to serve as a basis for comparison with extragalactic results. This study combines new observations of HCN, CS, and CO in individual GMCs and in the Milky Way plane with…

Astrophysics · Physics 2009-10-28 Tamara T. Helfer , Leo Blitz

An imaging survey of CO(1-0), HCN(1-0), and HCO$^+$(1-0) lines in the centers of nearby Seyfert galaxies has been conducted using the Nobeyama Millimeter Array and the RAINBOW interferometer. Preliminary results reveal that 3 Seyferts out…

We present observations of the dense molecular gas tracers HCN, HNC, and HCO+ in the J=1-0 transition using ALMA. We supplement our datasets with previous observations of CO J=1-0, which traces the total molecular gas content. We separate…

Astrophysics of Galaxies · Physics 2016-06-01 Maximilien R. P. Schirm , Christine D. Wilson , Suzanne C. Madden , Dave L. Clements

(abridged) HCN luminosity Lhcn is a tracer of DENSE molecular gas, n(H_2) >~ 3x10^4 cm^{-3}, associated with star-forming giant molecular cloud (GMC) cores. We present the results and analysis of our survey of HCN emission from 65 infrared…

Astrophysics · Physics 2009-08-21 Yu Gao , Philip M. Solomon

We report a sensitive search for the HCN(J=2-1) emission line towards SDSS J1148+5251 at z=6.42 with the VLA. HCN emission is a star formation indicator, tracing dense molecular hydrogen gas (n(H2) >= 10^4 cm^-3) within star-forming…

Astrophysics · Physics 2008-07-12 Dominik A. Riechers , Fabian Walter , Christopher L. Carilli , Frank Bertoldi

We have imaged the central ~1kpc of the circumnuclear starburst disk in the galaxy NGC253 in the HCN(1-0), HCO+(1-0), and CO(1-0) transitions at 60pc resolution using the Owens Valley Radio Observatory Millimeter-Wavelength Array (OVRO). We…

Astrophysics · Physics 2009-06-23 K. K. Knudsen , F. Walter , A. Weiss , A. Bolatto , D. A. Riechers , K. Menten

Giant Molecular Filaments are opportune locations in our Galaxy to study the star-forming interstellar matter and its accumulation on spatial scales comparable to those now becoming available for external galaxies. We mapped the emission of…

Astrophysics of Galaxies · Physics 2025-06-12 O. Feher , S. E. Ragan , F. D. Priestley , P. C. Clark

We present 3 mm and 2 mm band simultaneously spectroscopic observations of HCN 1-0, HCO$^{+}$ 1-0, HNC 1-0, and CS 3-2 with the IRAM 30 meter telescope, toward a sample of 70 sources as nearby galaxies with infrared luminosities ranging…

Astrophysics of Galaxies · Physics 2021-03-24 Fei Li , Junzhi Wang , Feng Gao , Shu Liu , Zhi-Yu Zhang , Shanghuo Li , Yan Gong , Juan Li , Yong Shi

Trends observed in galaxies, such as the Gao \& Solomon relation, suggest a linear relation between the star formation rate and the mass of dense gas available for star formation. Validation of such relations requires the establishment of…

Astrophysics of Galaxies · Physics 2017-09-20 Jens Kauffmann , Paul F. Goldsmith , Gary Melnick , Volker Tolls , Andres Guzman , Karl M. Menten

To study the high-transition dense-gas tracers and their relationships to the star formation of the inner $\sim$ 2 kpc circumnuclear region of NGC253, we present HCN $J=4-3$ and HCO$^+ J=4-3$ maps obtained with the James Clerk Maxwell…

Using the IRAM 30m telescope, we have surveyed an unbiased sample of 47 nearby spiral galaxies of very late (Scd-Sm) Hubble-type for emission in the CO(1-0) and CO(2-1) lines. The sensitivity of our data (a few mK) allows detection of about…

Astrophysics · Physics 2009-11-07 T. Boeker , U. Lisenfeld , E. Schinnerer

We report results of a project to map HCN and HCO+ J = 1-0 emission toward a sample of molecular clouds in the inner Galaxy, all containing dense clumps that are actively engaged in star formation. We compare these two molecular line…

Astrophysics of Galaxies · Physics 2020-05-20 Neal J. Evans , Kee-Tae Kim , Jingwen Wu , Zhang Chao , Mark Heyer , Tie Liu , Quang Nguyen-Luong , Jens Kauffmann

We present the first survey of dense gas towards Planck Galactic Cold Clumps (PGCCs). Observations in the J=1-0 transitions of HCO+ and HCN towards 621 molecular cores associated with PGCCs were performed using the Purple Mountain…

Astrophysics of Galaxies · Physics 2016-03-23 Jinghua Yuan , Yuefang Wu , Tie Liu , Tianwei Zhang , Jin Zeng Li , Hong-Li Liu , Fanyi Meng , Ping Chen , Runjie Hu , Ke Wang

The Galactic Center regions $-6^\circ \le l \le 6^\circ$ and $-0.8^\circ \le b \le 0.87^\circ$ are surveyed with HCN J=1$-$0 line (88.6 GHz) on a 4$'$ grid with the 14 m telescope at the Taeduk Radio Astronomy Observatory. The data…

Astrophysics · Physics 2009-10-28 Chang Won Lee

In a pilot project to study the relationship between star formation and molecular gas properties in nearby normal early-type galaxies, we used the IRAM 30m telescope to observe the 13CO(J=1-0), 13CO(J=2-1), HCN(J=1-0) and HCO+(J=1-0) line…

Astrophysics of Galaxies · Physics 2015-05-19 M. Krips , A. F. Crocker , M. Bureau , F. Combes , L. M. Young

We use archival ALMA observations of the HCN and CO $J=1-0$ transitions, in addition to the radio continuum at 93 GHz, to assess the relationship between dense gas, star formation, and gas dynamics in ten, nearby (U)LIRGs and late-type…

Astrophysics of Galaxies · Physics 2023-03-15 Ashley R. Bemis , Christine D. Wilson

We model emissivities of the HCN and CO $J=1-0$ transitions using measured properties of clouds found in normal star forming galaxies and more extreme systems. These models are compared with observations of HCN and CO $J=1-0$ transitions.…

Astrophysics of Galaxies · Physics 2025-01-27 Ashley R. Bemis , Christine D. Wilson , Piyush Sharda , Ian D. Roberts , Hao He