The Unusual AGN Host NGC 1266:Evidence for Shocks in a Molecular Gas Rich S0 Galaxy with a Low Luminosity Nucleus  

作　　者：Peibin Chen Yinghe Zhao Junfeng Wang 

机构地区：[1]Department of Astronomy,Xiamen University,Xiamen 361005,China [2]Yunnan Observatories,Chinese Academy of Sciences,Kunming 650011,China

出　　处：《Research in Astronomy and Astrophysics》2023年第1期48-59,共12页天文和天体物理学研究（英文版）

基　　金：supported by the National Natural Science Foundation of China(NSFC Grant Nos.12033004,U1831205,12173079 and 12221003);the science research grants from the China Manned Space Project with Nos.CMS-CSST-2021A06 and CMS-CSST-2021-B02。

摘　　要：NGC 1266 is a lenticular galaxy(S0)hosting an active galactic nucleus(AGN),and known to contain a large amount of shocked gas.We compare the luminosity ratio of mid-J CO lines to IR continuum with star-forming galaxies(SFGs),and then model the CO spectral line energy distribution(SLED).We confirm that in the mid-and high-J regions(J_(up)=4-13),the C-type shock(v_(s)=25 km s^(-1),n_(H)=5×10^(4)cm^(-3))can reproduce the CO observations well.The galaxy spectral energy distribution(SED)is constructed and modeled by the code X-CIGALE and obtains a set of physical parameters including the star formation rate(SFR,1.17±0.47 M_(⊙)yr^(-1)).Also,our work provides SFR derivation of[C II]from the neutral hydrogen regions only(1.38±0.14 M_(⊙)yr^(-1)).Previous studies have illusive conclusions on the AGN or starburst nature of the NGC 1266 nucleus.Our SED model shows that the hidden AGN in the system is intrinsically low-luminosity,consequently the infrared luminosity of the AGN does not reach the expected level.Archival data from Nu STAR hard X-ray observations in the 3-79 keV band shows a marginal detection,disfavoring presence of an obscured luminous AGN and implying that a compact starburst is more likely dominant for the NGC 1266 nucleus.

关 键 词：GALAXIES elliptical and lenticular-cD-galaxies individual(NGC 1266)-galaxies ISM-galaxies star formation-galaxies active 

分 类 号：P15[天文地球—天文学]