Carbon and oxygen isotope ratios in starburst galaxies: New data from NGC 253 and Mrk 231 and their implications

CORC > 紫金山天文台 > 中国科学院紫金山天文台 > 近地天体探测和太阳系天体研究团组

	Carbon and oxygen isotope ratios in starburst galaxies: New data from NGC 253 and Mrk 231 and their implications
	Henkel, C.1,2; Asiri, H.2; Ao, Y.1,3,4; Aalto, S.5; Danielson, A. L. R.6; Papadopoulos, P. P.7,8; Garcia-Burillo, S.9; Aladro, R.10; Impellizzeri, C. M. V.10; Mauersberger, R.10
刊名	ASTRONOMY & ASTROPHYSICS
	2014-05-01
卷号	565 期号:0 页码:0
关键词	galaxies: starburst galaxies: abundances galaxies: ISM nuclear reactions, nucleosynthesis, abundances galaxies: individual: NGC 253 galaxies: individual: Mrk 231
ISSN号	0004-6361
英文摘要	Carbon and oxygen isotope ratios are excellent measures of nuclear processing, but few such data have been taken toward extragalactic targets so far. Therefore, using the IRAM 30-m telescope, CN and CO isotopologues have been measured toward the nearby starburst galaxy NGC 253 and the prototypical ultraluminous infrared galaxy Mrk 231. Toward the center of NGC 253, the CN and (CN)-C-13 N = 1 -> 0 lines indicate no significant deviations from expected local thermodynamical equilibrium after accounting for moderate saturation effects (10 and 25%) in the two detected spectral components of the main species. Including calibration uncertainties, which dominate the error budget, the C-12/C-13 ratio becomes 40 +/- 10. This is larger than the ratio in the central molecular zone of the Galaxy, suggesting a higher infall rate of poorly processed gas toward the central region. Assuming that the ratio also holds for the CO emitting gas, this yields O-16/O-18 = 145 +/- 36 and O-16/O-17 = 1290 +/- 365 and a S-32/S-34 ratio close to the one measured for the local interstellar medium (2025). No indication of vibrationally excited CN is found in the lower frequency fine structure components of the N = 1 -> 0 and 2 -> 1 transitions at rms noise levels of 3 and 4 mK (15 and 20 mJy) in 8.5 km s-1 wide channels. Peak line intensity ratios between NGC 253 and Mrk 231 are similar to 100 for (CO)-C-12-O-16 and (CO)-C-12-O-18 J = 1 -> 0, while the ratio for (CO)-C-13-O-16 J = 1 -> 0 is similar to 250. This and similar (CO)-C-13 and (CO)-O-18 line intensities in the J = 1 -> 0 and 2 -> 1 transitions of Mrk 231 suggest C-12/C-13 similar to 100 and O-16/O-18 similar to 100, in agreement with values obtained for the less evolved ultraluminous merger Arp 220. Also, when accounting for other (scarcely available) extragalactic data, C-12/C-13 ratios appear to vary over a full order of magnitude, from >100 in ultraluminous high redshift galaxies to similar to 100 in more local such galaxies to similar to 40 in weaker starbursts that are not undergoing a large scale merger to 25 in the central molecular zone of the Milky Way. With C-12 being predominantly synthesized in massive stars, while C-13 is mostly ejected by longer lived lower mass stars at later times, this is qualitatively consistent with our results of decreasing carbon isotope ratios with time and rising metallicity. It is emphasized, however, that both infall of poorly processed material, initiating a nuclear starburst, and the ejecta from newly formed massive stars (in particular in the case of a top-heavy stellar initial mass function) can raise the carbon isotope ratio for a limited amount of time.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	(CO)-C-13 J=1-0 DEPRESSION ; RED GIANT BRANCH ; DENSE GAS ; NEARBY GALAXIES ; NUCLEAR STARBURST ; GALACTIC-CENTER ; STAR-FORMATION ; MOLECULAR GAS ; INTENSITY RATIOS ; VLA OBSERVATIONS
收录类别	SCI
原文出处	10.1051/0004-6361/201322962
语种	英语
WOS记录号	WOS:000336730900003
公开日期	2014-11-20
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/10670]
专题	紫金山天文台_近地天体探测和太阳系天体研究团组
作者单位	1.Max Planck Inst Radioastron, D-53121 Bonn, Germany 2.King Abdulaziz Univ, Fac Sci, Dept Astron, Jeddah 21589, Saudi Arabia 3.Chinese Acad Sci, Purple Mt Observ, Nanjing 21008, Jiangsu, Peoples R China 4.Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan 5.Chalmers, Dept Earth & Space Sci, Onsala Observ, S-43994 Onsala, Sweden 6.Univ Durham, Dept Phys, Inst Computat Cosmol, Durham DH1 3LE, England 7.Cardiff Univ, Sch Phys, Cardiff CF24 3AA, S Glam, Wales 8.European So Observ, D-85748 Garching, Germany 9.Observ Madrid, OAN, Madrid 28014, Spain 10.European So Observ, Santiago 19001, Chile
推荐引用方式 GB/T 7714	Henkel, C.,Asiri, H.,Ao, Y.,et al. Carbon and oxygen isotope ratios in starburst galaxies: New data from NGC 253 and Mrk 231 and their implications[J]. ASTRONOMY & ASTROPHYSICS,2014,565(0):0.
APA	Henkel, C..,Asiri, H..,Ao, Y..,Aalto, S..,Danielson, A. L. R..,...&Harada, N..(2014).Carbon and oxygen isotope ratios in starburst galaxies: New data from NGC 253 and Mrk 231 and their implications.ASTRONOMY & ASTROPHYSICS,565(0),0.
MLA	Henkel, C.,et al."Carbon and oxygen isotope ratios in starburst galaxies: New data from NGC 253 and Mrk 231 and their implications".ASTRONOMY & ASTROPHYSICS 565.0(2014):0.