HST FUV Spectroscopy of Super Star Cluster A in the Green Pea Analog Mrk 71: Revealing the Presence of Very Massive Stars
Linda J. Smith, M. S. Oey, Svea Hernandez, Jenna Ryon, Claus Leitherer, Stephane Charlot, Gustavo Bruzual, Daniela Calzetti, You-Hua Chu, Matthew J. Hayes, Beth… 展开作者
Linda J. Smith, M. S. Oey, Svea Hernandez, Jenna Ryon, Claus Leitherer, Stephane Charlot, Gustavo Bruzual, Daniela Calzetti, You-Hua Chu, Matthew J. Hayes, Bethan L. James, Anne. E. Jaskot, Goeran Oestlin
Mrk 71 is a low metallicity (Z = 0.16 Z_sun) starburst region in the local dwarf galaxy NGC 2366, hosting two super star clusters (SSCs A and B), and is recognized as a Green Pea (GP) analog with SSC A responsible for the GP properties. We present STIS and FOS far-ultraviolet (FUV) spectra of the embedded SSC Mrk 71-A obtained with the Hubble Space Telescope (HST). The STIS FUV spectrum shows the characteristic features of very massive stars (VMS, masses > 100 M_sun) and we derive an age of 1+/-1 Myr by comparison with the Charlot & Bruzual suite of spectral population synthesis models with upper mass limits of 300 and 600 M_sun. We compare the STIS spectrum with all known SSC spectra exhibiting VMS signatures: NGC 5253-5, R136a, NGC 3125-A1 and the z = 2.37 Sunburst cluster. We find that the cluster mass-loss rates and wind velocities, as characterized by the C IV P Cygni profiles and the He II emission line strengths, are very similar over Z = 0.16 to 0.4 Z_sun. This agrees with predictions that the optically thick winds of VMS will be enhanced near the Eddington limit and show little metallicity dependence. We find very strong damped Lyman-alpha absorption with log N(H I) = 22.2 cm-2 associated with Mrk 71-A. We discuss the natal environment of this young SSC in terms of radiatively-driven winds, catastrophic cooling and recent models where the cluster is surrounded by highly pressurized clouds with large neutral columns.
NGC 6860, Mrk 915, and MCG -01-24-012. II. Inflowing and outflowing cold molecular gas and the connection with ionized gas in Seyfert galaxies
Zentrum für Astronomie der Universität Heidelberg, Astronomisches Rechen-Institut（海德堡大学天文中心，天文计算研究所）；Departamento de Astronomia, Universidade Federal do Rio Grande do Sul（南里奥格兰德联邦大学天文学系）；Astronomy Department, Universidad de Concepción（康塞普西翁大学天文学系）；Observatorio Astronómico Nacional (OAN-IGN)-Observatorio de Madrid（国家天文台（OAN-IGN）马德里天文台）；Departamento de Física, CCNE, Universidade Federal de Santa Maria（圣玛丽亚联邦大学物理系，CCNE）；Centro de Astrobiología (CAB), CSIC-INTA（西班牙国家技术研究委员会-国家航空航天技术研究所天体生物学中心）；Finnish Centre for Astronomy with ESO, University of Turku（图尔库大学芬兰ESO天文学中心）
Churchill Scholar（丘吉尔学者）；Cavendish Laboratory, Department of Physics, University of Cambridge（剑桥大学物理系卡文迪许实验室）；Institute for Astronomy, University of Hawai‘i（夏威夷大学天体物理研究所）；Department of Physics and Astronomy, Pomona College（波莫纳学院物理与天文系）；FINESST FI；Department of Astronomy, The Ohio State University（俄亥俄州立大学天文系）；Center for Cosmology and Astroparticle Physics, The Ohio State University（俄亥俄州立大学宇宙学与亚原子物理中心）；Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney（悉尼大学物理学院悉尼天体物理研究所）
