Molecular gas kinematics and line diagnostics in early-type galaxies: NGC4710 and NGC5866Report as inadecuate




Molecular gas kinematics and line diagnostics in early-type galaxies: NGC4710 and NGC5866 - Download this document for free, or read online. Document in PDF available to download.

Reference: Bureau, M, Topal, S, Davis, TA et al., (2016). Molecular gas kinematics and line diagnostics in early-type galaxies: NGC4710 & NGC5866. Monthly Notices of the Royal Astronomical Society, 463 (4), 4121-4152.Citable link to this page:

 

Molecular gas kinematics and line diagnostics in early-type galaxies: NGC4710 & NGC5866

Abstract: We present interferometric observations of CO lines (12CO(1-0, 2-1) and 13CO(1-0, 2-1)) and dense gas tracers (HCN(1-0), HCO+ (1-0), HNC(1-0) and HNCO(4-3)) in two nearby edgeon barred lenticular galaxies, NGC 4710 and NGC 5866, with most of the gas concentrated in a nuclear disc and an inner ring in each galaxy. We probe the physical conditions of a two-component molecular interstellar medium in each galaxy and each kinematic component by using molecular line ratio diagnostics in three complementary ways. First, we measure the ratios of the position-velocity diagrams of different lines, second we measure the ratios of each kinematic component’s integrated line intensities as a function of projected position, and third we model these line ratios using a non-local thermodynamic equilibrium radiative transfer code. Overall, the nuclear discs appear to have a tenuous molecular gas component that is hotter, optically thinner and with a larger dense gas fraction than that in the inner rings, suggesting more dense clumps immersed in a hotter more diffuse molecular medium. This is consistent with evidence that the physical conditions in the nuclear discs are similar to those in photo-dissociation regions. A similar picture emerges when comparing the observed molecular line ratios with those of other galaxy types. The physical conditions of the molecular gas in the nuclear discs of NGC 4710 and NGC 5866 thus appear intermediate between those of spiral galaxies and starbursts, while the star formation in their inner rings is even milder.

Publication status:PublishedPeer Review status:Peer reviewedVersion:Accepted manuscriptDate of acceptance:2016-09-06 Funder: Seventh Framework Programme   Funder: Science and Technology Facilities Council   Notes:© 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society

Bibliographic Details

Publisher: Oxford University Press

Publisher Website: http://www.oxfordjournals.org/

Journal: Monthly Notices of the Royal Astronomical Societysee more from them

Publication Website: http://mnras.oxfordjournals.org/

Volume: 463

Issue: 4

Extent: 4121-4152

Issue Date: 2016-09

pages:4121-4152Identifiers

Doi: https://doi.org/10.1093/mnras/stw2257

Issn: 1365-2966

Uuid: uuid:a84e1202-0943-4930-a5f8-badf90beaf40

Urn: uri:a84e1202-0943-4930-a5f8-badf90beaf40

Pubs-id: pubs:656091 Item Description

Type: journal-article;

Version: Accepted manuscriptKeywords: galaxies: lenticulars galaxies: individual: NGC 4710 and NGC 5866 galaxies: ISM ISM: molecules

Relationships





Author: Bureau, M - Oxford, MPLS, Physics, Astrophysics fundingUK Research Councils grantNumberST-H002456-1 grantNumberST-K00106X-1 - - -

Source: https://ora.ox.ac.uk/objects/uuid:a84e1202-0943-4930-a5f8-badf90beaf40



DOWNLOAD PDF




Related documents