Статья

Two New Calcium-rich Gap Transients in Group and Cluster Environments

R. LunnanDepartment of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; [email protected]M. M. KasliwalDepartment of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; [email protected]Y. CaoDepartment of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; [email protected]L. HangardOskar Klein Centre, Physics Department, Stockholm University, SE-106 91 Stockholm, SwedenO. YaronBenoziyo Center for Astrophysics and the Helen Kimmel Center for Planetary Science, Weizmann Institute of Science, 76100 Rehovot, IsraelJ. ParrentHarvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USACurtis McCullyDepartment of Physics, University of California, Santa Barbara, Broida Hall, Mail Code 9530, Santa Barbara, CA 93106-9530, USAA. Gal‐YamBenoziyo Center for Astrophysics and the Helen Kimmel Center for Planetary Science, Weizmann Institute of Science, 76100 Rehovot, IsraelJohn S. MulchaeyThe Observatories of the Carnegie Institution for Science, Pasadena, CA 91101, USASagi Ben-AmiHarvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USAA. V. FilippenkoDepartment of Astronomy, University of California, Berkeley, CA 94720-3411, USAC. FremlingOskar Klein Centre, Physics Department, Stockholm University, SE-106 91 Stockholm, SwedenA. S. FruchterSpace Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218, USAD. A. HowellDepartment of Physics, University of California, Santa Barbara, Broida Hall, Mail Code 9530, Santa Barbara, CA 93106-9530, USAJin KodaDepartment of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800, USAT. KupferDepartment of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; [email protected]S. R. KulkarniDepartment of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA; [email protected]Russ R. LaherSpitzer Science Center, California Institute of Technology, MS 314-6, Pasadena, CA 91125, USAFrank J. MasciInfrared Processing and Analysis Center, California Institute of Technology, MS 100-22, Pasadena, CA 91125, USAP. NugentDepartment of Astronomy, University of California, Berkeley, CA 94720-3411, USAE. O. OfekBenoziyo Center for Astrophysics and the Helen Kimmel Center for Planetary Science, Weizmann Institute of Science, 76100 Rehovot, IsraelMasafumi YagiOptical and Infrared Astronomy Division, National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo, 181-8588, JapanLin YanCaltech Optical Observatories, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA

2017en

ABI

Аннотация

Abstract 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 , while Hubble Space Telescope imaging of PTF11kmb reveals a marginal counterpart that, if real, could be either a background galaxy or a globular cluster. 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. 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.

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Идентификаторы

DOI: 10.3847/1538-4357/836/1/60

Цитирования и источники

Цитирований: 2Использованных источников: 0

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