Two New Calcium-rich Gap Transients in Group and Cluster Environments [electronic resource].
- Washington, D.C. : United States. Dept. of Energy. Office of Science, 2017. and Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- Article numbers 60 : digital, PDF file
- Additional Creators:
- Lawrence Berkeley National Laboratory, United States. Department of Energy. Office of Science, National Science Foundation (U.S.), and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- We present the Palomar Transient Factory discoveries and the photometric and spectroscopic observations of PTF11kmb and PTF12bho. We show that both transients have properties consistent with the class of calcium-rich gap transients, specifically lower peak luminosities and rapid evolution compared to ordinary supernovae, and a nebular spectrum dominated by [Ca ii] emission. A striking feature of both transients is their host environments: PTF12bho is an intracluster transient in the Coma Cluster, while PTF11kmb is located in a loose galaxy group, at a physical offset ~150 kpc from the most likely host galaxy. Deep Subaru imaging of PTF12bho rules out an underlying host system to a limit of M<sub>R</sub> > -8.0 mag, while Hubble Space Telescope imaging of PTF11kmb reveals a marginal counterpart that, if real, could be either a background galaxy or a globular cluster. Here, we show that the offset distribution of Ca-rich gap transients is significantly more extreme than that seen for SNe Ia or even short-hard gamma-ray bursts (sGRBs). Thus, if the offsets are caused by a kick, they require higher kick velocities and/or longer merger times than sGRBs. Finally, we also show that almost all Ca-rich transients found to date are in group and cluster environments with elliptical host galaxies, indicating a very old progenitor population; the remote locations could partially be explained by these environments having the largest fraction of stars in the intragroup/intracluster light following galaxy-galaxy interactions.
- Published through SciTech Connect., 02/08/2017., "ark:/13030/qt0mb7c6j5", The Astrophysical Journal (Online) 836 1 ISSN 1538-4357 AM, R. Lunnan; M. M. Kasliwal; Y. Cao; L. Hangard; O. Yaron; J. T. Parrent; C. McCully; A. Gal-Yam; J. S. Mulchaey; S. Ben-Ami; A. V. Filippenko; C. Fremling; A. S. Fruchter; D. A. Howell; J. Koda; T. Kupfer; S. R. Kulkarni; R. Laher; F. Masci; P. E. Nugent; E. O. Ofek; M. Yagi; Lin Yan., and Gordon and Betty Moore Foundation
- Funding Information:
- AC02-05CH11231, AST-1211916, AST-313484, 307260, NAS 5-26555, and GBMF5076
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