Final published version
Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Studying the Ultraviolet Spectrum of the First Spectroscopically Confirmed Supernova at Redshift Two
AU - Dark Energy Survey Collaboration
AU - Smith, M.
AU - Sullivan, M.
AU - Nichol, R.~C.
AU - Galbany, L.
AU - D'Andrea, C.~B.
AU - Inserra, C.
AU - Lidman, C.
AU - Rest, A.
AU - Schirmer, M.
AU - Filippenko, A.~V.
AU - Zheng, W.
AU - Cenko, S. Bradley
AU - Angus, C.~R.
AU - Brown, P.~J.
AU - Davis, T.~M.
AU - Finley, D.~A.
AU - Foley, R.~J.
AU - González-Gaitán, S.
AU - Gutiérrez, C.~P.
AU - Kessler, R.
AU - Kuhlmann, S.
AU - Marriner, J.
AU - Möller, A.
AU - Nugent, P.~E.
AU - Prajs, S.
AU - Thomas, R.
AU - Wolf, R.
AU - Zenteno, A.
AU - Abbott, T.~M.~C.
AU - Abdalla, F.~B.
AU - Allam, S.
AU - Annis, J.
AU - Bechtol, K.
AU - Benoit-Lévy, A.
AU - Bertin, E.
AU - Brooks, D.
AU - Burke, D.~L.
AU - Carnero Rosell, A.
AU - Carrasco Kind, M.
AU - Carretero, J.
AU - Castander, F.~J.
AU - Crocce, M.
AU - Cunha, C.~E.
AU - da Costa, L.~N.
AU - Davis, C.
AU - Desai, S.
AU - Diehl, H.~T.
AU - Doel, P.
AU - Eifler, T.~F.
AU - Flaugher, B.
PY - 2018/2/8
Y1 - 2018/2/8
N2 - We present observations of DES16C2nm, the first spectroscopically confirmed hydrogen-free superluminous supernova (SLSN-I) at redshift z≈ 2. DES16C2nm was discovered by the Dark Energy Survey (DES) Supernova Program, with follow-up photometric data from the Hubble Space Telescope, Gemini, and the European Southern Observatory Very Large Telescope supplementing the DES data. Spectroscopic observations confirm DES16C2nm to be at z = 1.998, and spectroscopically similar to Gaia16apd (a SLSN-I at z = 0.102), with a peak absolute magnitude of U=-22.26+/- 0.06. The high redshift of DES16C2nm provides a unique opportunity to study the ultraviolet (UV) properties of SLSNe-I. Combining DES16C2nm with 10 similar events from the literature, we show that there exists a homogeneous class of SLSNe-I in the UV ({λ }{rest}≈ 2500 Å), with peak luminosities in the (rest-frame) U band, and increasing absorption to shorter wavelengths. There is no evidence that the mean photometric and spectroscopic properties of SLSNe-I differ between low (z< 1) and high redshift (z> 1), but there is clear evidence of diversity in the spectrum at {λ }{rest}< 2000 \mathringA , possibly caused by the variations in temperature between events. No significant correlations are observed between spectral line velocities and photometric luminosity. Using these data, we estimate that SLSNe-I can be discovered to z = 3.8 by DES. While SLSNe-I are typically identified from their blue observed colors at low redshift (z< 1), we highlight that at z> 2 these events appear optically red, peaking in the observer-frame z-band. Such characteristics are critical to identify these objects with future facilities such as the Large Synoptic Survey Telescope, Euclid, and the Wide-field Infrared Survey Telescope, which should detect such SLSNe-I to z = 3.5, 3.7, and 6.6, respectively.
AB - We present observations of DES16C2nm, the first spectroscopically confirmed hydrogen-free superluminous supernova (SLSN-I) at redshift z≈ 2. DES16C2nm was discovered by the Dark Energy Survey (DES) Supernova Program, with follow-up photometric data from the Hubble Space Telescope, Gemini, and the European Southern Observatory Very Large Telescope supplementing the DES data. Spectroscopic observations confirm DES16C2nm to be at z = 1.998, and spectroscopically similar to Gaia16apd (a SLSN-I at z = 0.102), with a peak absolute magnitude of U=-22.26+/- 0.06. The high redshift of DES16C2nm provides a unique opportunity to study the ultraviolet (UV) properties of SLSNe-I. Combining DES16C2nm with 10 similar events from the literature, we show that there exists a homogeneous class of SLSNe-I in the UV ({λ }{rest}≈ 2500 Å), with peak luminosities in the (rest-frame) U band, and increasing absorption to shorter wavelengths. There is no evidence that the mean photometric and spectroscopic properties of SLSNe-I differ between low (z< 1) and high redshift (z> 1), but there is clear evidence of diversity in the spectrum at {λ }{rest}< 2000 \mathringA , possibly caused by the variations in temperature between events. No significant correlations are observed between spectral line velocities and photometric luminosity. Using these data, we estimate that SLSNe-I can be discovered to z = 3.8 by DES. While SLSNe-I are typically identified from their blue observed colors at low redshift (z< 1), we highlight that at z> 2 these events appear optically red, peaking in the observer-frame z-band. Such characteristics are critical to identify these objects with future facilities such as the Large Synoptic Survey Telescope, Euclid, and the Wide-field Infrared Survey Telescope, which should detect such SLSNe-I to z = 3.5, 3.7, and 6.6, respectively.
KW - distance scale
KW - supernovae: general
KW - supernovae: individual: DES16C2nm
KW - surveys
KW - Astrophysics - High Energy Astrophysical Phenomena
KW - Astrophysics - Cosmology and Nongalactic Astrophysics
KW - Astrophysics - Astrophysics of Galaxies
KW - Astrophysics - Solar and Stellar Astrophysics
U2 - 10.3847/1538-4357/aaa126
DO - 10.3847/1538-4357/aaa126
M3 - Journal article
VL - 854
SP - 37
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 1
ER -