SN REFSDAL: PHOTOMETRY AND TIME DELAY MEASUREMENTS OF THE FIRST EINSTEIN CROSS SUPERNOVA

Journal Article · Sun Mar 20 00:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/820/1/50· OSTI ID:22521415

Rodney, S. A. ^[1]; Strolger, L. -G.; Brammer, G. ^[2]; Kelly, P. L.; Filippenko, A. V. ^[3]; Bradač, M. ^[4]; Foley, R. J. ^[5]; Graur, O. ^[6]; Hjorth, J.; Selsing, J. ^[7]; Jha, S. W. ^[8]; McCully, C. ^[9]; Molino, A. ^[10]; Riess, A. G. ^[11]; Schmidt, K. B. ^[12]; Sharon, K. ^[13]; Treu, T. ^[14]; others, and

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1. Department of Physics and Astronomy, University of South Carolina, 712 Main St., Columbia, SC 29208 (United States)
2. Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)
3. Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
4. University of California Davis, 1 Shields Avenue, Davis, CA 95616 (United States)
5. Department of Physics, University of Illinois at Urbana-Champaign, 1110 W. Green Street, Urbana, IL 61801 (United States)
6. Center for Cosmology and Particle Physics, New York University, New York, NY 10003 (United States)
7. Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark)
8. Department of Physics and Astronomy, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 (United States)
9. Las Cumbres Observatory Global Telescope Network, 6740 Cortona Dr., Suite 102, Goleta, California 93117 (United States)
10. Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Cidade Universitária, 05508-090, São Paulo (Brazil)
11. Department of Physics and Astronomy, The Johns Hopkins University, 3400N. Charles St., Baltimore, MD 21218 (United States)
12. Department of Physics, University of California, Santa Barbara, CA 93106-9530 (United States)
13. Department of Astronomy, University of Michigan, 1085 S. University Avenue, Ann Arbor, MI 48109 (United States)
14. Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States)

We present the first year of Hubble Space Telescope imaging of the unique supernova (SN) “Refsdal,” a gravitationally lensed SN at z = 1.488 ± 0.001 with multiple images behind the galaxy cluster MACS J1149.6+2223. The first four observed images of SN Refsdal (images S1–S4) exhibited a slow rise (over ∼150 days) to reach a broad peak brightness around 2015 April 20. Using a set of light curve templates constructed from SN 1987A-like peculiar Type II SNe, we measure time delays for the four images relative to S1 of 4 ± 4 (for S2), 2 ± 5 (S3), and 24 ± 7 days (S4). The measured magnification ratios relative to S1 are 1.15 ± 0.05 (S2), 1.01 ± 0.04 (S3), and 0.34 ± 0.02 (S4). None of the template light curves fully captures the photometric behavior of SN Refsdal, so we also derive complementary measurements for these parameters using polynomials to represent the intrinsic light curve shape. These more flexible fits deliver fully consistent time delays of 7 ± 2 (S2), 0.6 ± 3 (S3), and 27 ± 8 days (S4). The lensing magnification ratios are similarly consistent, measured as 1.17 ± 0.02 (S2), 1.00 ± 0.01 (S3), and 0.38 ± 0.02 (S4). We compare these measurements against published predictions from lens models, and find that the majority of model predictions are in very good agreement with our measurements. Finally, we discuss avenues for future improvement of time delay measurements—both for SN Refsdal and for other strongly lensed SNe yet to come.

• OSTI ID: 22521415
• Journal Information: Astrophysical Journal, Vol. 820, Issue 1; 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
BRIGHTNESS
COMPARATIVE EVALUATIONS
DIAGRAMS
GALAXY CLUSTERS
GRAVITATIONAL LENSES
IMAGES
PHOTOMETRY
SPACE
SUPERNOVAE
TELESCOPES
TIME DELAY
VISIBLE RADIATION