A 2-3 mm high-resolution molecular line survey towards the centre of the nearby spiral galaxy NGC 6946
| العنوان: | A 2-3 mm high-resolution molecular line survey towards the centre of the nearby spiral galaxy NGC 6946 |
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| المؤلفون: | Eibensteiner, Cosima, Barnes, Ashley T., Bigiel, Frank, Schinnerer, Eva, Liu, Daizhong, Meier, David S., Usero, Antonio, Leroy, Adam K., Rosolowsky, Erik, Puschnig, Johannes, Lazar, Ilin, Pety, J��r��me, Lopez, Laura A., Emsellem, Eric, Be��li��, Ivana, Querejeta, Miguel, Murphy, Eric J., Brok, Jakob den, Schruba, Andreas, Chevance, M��lanie, Glover, Simon C. O., Gao, Yu, Grasha, Kathryn, Hassani, Hamid, Henshaw, Jonathan D., Jimenez-Donaire, Maria J., Klessen, Ralf S., Kruijssen, J. M. Diederik, Pan, Hsi-An, Saito, Toshiki, Sormani, Mattia C., Teng, Yu-Hsuan, Williams, Thomas G. |
| المساهمون: | Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
| المصدر: | A&A Cosima Eibensteiner Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, 2022, 659, ⟨10.1051/0004-6361/202142624⟩ |
| سنة النشر: | 2022 |
| مصطلحات موضوعية: | [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, galaxies: ISM, ISM: molecules, galaxies: individual: NGC 6946 |
| الوصف: | The complex physical, kinematic, and chemical properties of galaxy centres make them interesting environments to examine with molecular line emission. We present new $2-4$" (${\sim}75{-}150$ pc at $7.7$ Mpc) observations at 2 and 3 mm covering the central $50$" (${\sim}1.9$ kpc) of the nearby double-barred spiral galaxy NGC 6946 obtained with the IRAM Plateau de Bure Interferometer. We detect spectral lines from ten molecules: CO, HCN, HCO$^+$, HNC, CS, HC$_3$N, N$_2$H$^+$, C$_2$H, CH$_3$OH, and H$_2$CO. We complemented these with published 1mm CO observations and 33 GHz continuum observations to explore the star formation rate surface density ${\Sigma_{\mathrm{SFR}}}$ on 150 pc scales. In this paper, we analyse regions associated with the inner bar of NGC 6946 $-$ the nuclear region (NUC), the northern (NBE), and southern inner bar end (SBE) and we focus on short-spacing corrected bulk (CO) and dense gas tracers (HCN, HCO$^+$, and HNC). We find that HCO$^+$ correlates best with ${\Sigma_{\mathrm{SFR}}}$, but the dense gas fraction ($f_{\mathrm{dense}}$) and star formation efficiency of the dense gas (${\mathrm{SFE_{dense}}}$) fits show different behaviours than expected from large-scale disc observations.The SBE has a higher ${\Sigma_{\mathrm{SFR}}}$, $f_{\mathrm{dense}}$, and shocked gas fraction than the NBE. We examine line ratio diagnostics and find a higher CO(2-1)/CO(1-0) ratio towards NBE than for the NUC. Moreover, comparison with existing extragalactic datasets suggests that using the HCN/HNC ratio to probe kinetic temperatures is not suitable on kiloparsec and sub-kiloparsec scales in extragalactic regions. Lastly, our study shows that the HCO$^+$/HCN ratio might not be a unique indicator to diagnose AGN activity in galaxies. Comment: 38 pages, 23 figures, accepted for publication in A&A |
| تدمد: | 0004-6361 |
| DOI: | 10.1051/0004-6361/202142624 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0e24881fb8a9176b45749ce9497d5441Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....0e24881fb8a9176b45749ce9497d5441 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 00046361 |
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| DOI: | 10.1051/0004-6361/202142624 |