SN REFSDAL: CLASSIFICATION AS A LUMINOUS AND BLUE SN 1987A-LIKE TYPE II SUPERNOVA

Journal Article · Thu Nov 10 00:00:00 EST 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/831/2/205· OSTI ID:22667205

Kelly, P. L.; Filippenko, A. V.; Graham, M. L. ^[1]; Brammer, G.; Strolger, L. -G.; Riess, A. G. ^[2]; Selsing, J.; Hjorth, J.; Christensen, L. ^[3]; Foley, R. J. ^[4]; Rodney, S. A. ^[5]; Treu, T. ^[6]; Steidel, C. C.; Strom, A.; Zitrin, A. ^[7]; Schmidt, K. B.; McCully, C. ^[8]; Bradač, M. ^[9]; Jha, S. W. ^[10]; others, and

---

1. Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
2. Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States)
3. Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)
4. Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, IL 61801 (United States)
5. Department of Physics and Astronomy, University of South Carolina, 712 Main St., Columbia, SC 29208 (United States)
6. University of California, Los Angeles, CA 90095 (United States)
7. California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)
8. Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States)
9. University of California, Davis, 1 Shields Avenue, Davis, CA 95616 (United States)
10. Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States)

We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in fall 2014. The HST light curve of SN Refsdal has a shape consistent with the distinctive, slowly rising light curves of SN 1987A-like SNe, and we find strong evidence for a broad H α P-Cygni profile and Na I D absorption in the HST grism spectrum at the redshift ( z = 1.49) of the spiral host galaxy. SNe IIn, largely powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show broad and strong H α and Na I D absorption. From the grism spectrum, we measure an H α expansion velocity consistent with those of SN 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the H α emission of the WFC3 and X-shooter spectra, separated by ∼2.5 months in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, photometry of SN Refsdal favors bluer B - V and V - R colors and one of the largest luminosities for the assumed range of potential magnifications. The evolution of the light curve at late times will provide additional evidence about the potential existence of any substantial circumstellar material. Using MOSFIRE and X-shooter spectra, we estimate a subsolar host-galaxy metallicity (8.3 ± 0.1 dex and <8.4 dex, respectively) near the explosion site.

• OSTI ID: 22667205
• Journal Information: Astrophysical Journal, Vol. 831, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ABSORPTION
CLASSIFICATION
COMPARATIVE EVALUATIONS
EMISSION
EXPANSION
EXPLOSIONS
GALAXIES
GALAXY CLUSTERS
GRAVITATIONAL LENSES
IMAGES
INFRARED SPECTRA
INTERACTIONS
LUMINOSITY
METALLICITY
PHOTOMETRY
RED SHIFT
STAR EVOLUTION
TELESCOPES
TYPE II SUPERNOVAE
VISIBLE RADIATION