The MALATANG survey: dense gas and star formation from high-transition HCN and HCO+ maps of NGC 253
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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The MALATANG survey : dense gas and star formation from high-transition HCN and HCO+ maps of NGC 253. / Jiang, Xue-Jian; Greve, Thomas R.; Gao, Yu; Zhang, Zhi-Yu; Tan, Qinghua; de Grijs, Richard; Ho, Luis C.; Michalowski, Michal J.; Currie, Malcolm J.; Wilson, Christine D.; Brinks, Elias; Ao, Yiping; Zhao, Yinghe; He, Jinhua; Harada, Nanase; Yang, Chentao; Jiao, Qian; Chung, Aeree; Lee, Bumhyun; Smith, Matthew W. L.; Liu, Daizhong; Matsushita, Satoki; Shi, Yong; Imanishi, Masatoshi; Rawlings, Mark G.; Zhu, Ming; Eden, David; Davis, Timothy A.; Li, Xiaohu.
I: Monthly Notices of the Royal Astronomical Society, Bind 494, Nr. 1, 01.05.2020, s. 1276-1296.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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TY - JOUR
T1 - The MALATANG survey
T2 - dense gas and star formation from high-transition HCN and HCO+ maps of NGC 253
AU - Jiang, Xue-Jian
AU - Greve, Thomas R.
AU - Gao, Yu
AU - Zhang, Zhi-Yu
AU - Tan, Qinghua
AU - de Grijs, Richard
AU - Ho, Luis C.
AU - Michalowski, Michal J.
AU - Currie, Malcolm J.
AU - Wilson, Christine D.
AU - Brinks, Elias
AU - Ao, Yiping
AU - Zhao, Yinghe
AU - He, Jinhua
AU - Harada, Nanase
AU - Yang, Chentao
AU - Jiao, Qian
AU - Chung, Aeree
AU - Lee, Bumhyun
AU - Smith, Matthew W. L.
AU - Liu, Daizhong
AU - Matsushita, Satoki
AU - Shi, Yong
AU - Imanishi, Masatoshi
AU - Rawlings, Mark G.
AU - Zhu, Ming
AU - Eden, David
AU - Davis, Timothy A.
AU - Li, Xiaohu
PY - 2020/5/1
Y1 - 2020/5/1
N2 - To study the high-transition dense-gas tracers and their relationships to the star formation of the inner similar to 2 kpc circumnuclear region of NGC 253, we present HCN J = 4-3 and HCO+ J = 4-3 maps obtained with the James Clerk Maxwell Telescope. Using the spatially resolved data, we compute the concentration indices r(90)/r(50) for the different tracers. HCN and HCO+ 4-3 emission features tend to be centrally concentrated, which is in contrast to the shallower distribution of CO 1-0 and the stellar component. The dense-gas fraction (f(dense), traced by v the velocity-integrated-intensity ratios of HCN/CO and HCO+/CO) and the ratio R-31 (CO 3-2 / 1 -0) decline towards larger galactocentric distances, but increase with higher star formation rate surface density. The radial variation and the large scatter of f(dense )- dense and R31 imply distinct physical conditions in different regions of the galactic disc. The relationships of f(dense) versus Sigma(stellar) and SFEdense versus Sigma(stellar) are explored. SFEdense increases with higher Sigma(stellar) in this galaxy, which is inconsistent with previous work that used HCN 1-0 data. This implies that existing stellar components might have different effects on the high-J HCN and HCO+ than their low-J emission. We also find that SFE(dense )seems to be decreasing with higher f(dense) which is consistent with previous works, and it suggests that the ability of the dense gas to form stars diminishes when the average density of the gas increases. This is expected in a scenario where only the regions with high-density contrast collapse and form stars.
AB - To study the high-transition dense-gas tracers and their relationships to the star formation of the inner similar to 2 kpc circumnuclear region of NGC 253, we present HCN J = 4-3 and HCO+ J = 4-3 maps obtained with the James Clerk Maxwell Telescope. Using the spatially resolved data, we compute the concentration indices r(90)/r(50) for the different tracers. HCN and HCO+ 4-3 emission features tend to be centrally concentrated, which is in contrast to the shallower distribution of CO 1-0 and the stellar component. The dense-gas fraction (f(dense), traced by v the velocity-integrated-intensity ratios of HCN/CO and HCO+/CO) and the ratio R-31 (CO 3-2 / 1 -0) decline towards larger galactocentric distances, but increase with higher star formation rate surface density. The radial variation and the large scatter of f(dense )- dense and R31 imply distinct physical conditions in different regions of the galactic disc. The relationships of f(dense) versus Sigma(stellar) and SFEdense versus Sigma(stellar) are explored. SFEdense increases with higher Sigma(stellar) in this galaxy, which is inconsistent with previous work that used HCN 1-0 data. This implies that existing stellar components might have different effects on the high-J HCN and HCO+ than their low-J emission. We also find that SFE(dense )seems to be decreasing with higher f(dense) which is consistent with previous works, and it suggests that the ability of the dense gas to form stars diminishes when the average density of the gas increases. This is expected in a scenario where only the regions with high-density contrast collapse and form stars.
KW - ISM: molecules
KW - galaxies: individual: NGC 253
KW - galaxies: ISM
KW - galaxies: star formation
KW - submillimetre: ISM
KW - MOLECULAR GAS
KW - NEARBY GALAXIES
KW - SPIRAL GALAXIES
KW - STARBURST
KW - TRACERS
KW - LUMINOSITY
KW - NUCLEUS
KW - NGC-253
U2 - 10.1093/mnras/staa794
DO - 10.1093/mnras/staa794
M3 - Journal article
VL - 494
SP - 1276
EP - 1296
JO - Royal Astronomical Society. Monthly Notices
JF - Royal Astronomical Society. Monthly Notices
SN - 0035-8711
IS - 1
ER -
ID: 319534229