Evidence for Type Ia Supernova Diversity from Ultraviolet Observations with the Hubble Space Telescope
Abstract
We present ultraviolet (UV) spectroscopy and photometry of four Type Ia supernovae (SNe 2004dt, 2004ef, 2005M, and 2005cf) obtained with the UV prism of the Advanced Camera for Surveys on the Hubble Space Telescope. This dataset provides unique spectral time series down to 2000 Angstrom. Significant diversity is seen in the near maximum-light spectra (~ 2000--3500 Angstrom) for this small sample. The corresponding photometric data, together with archival data from Swift Ultraviolet/Optical Telescope observations, provide further evidence of increased dispersion in the UV emission with respect to the optical. The peak luminosities measured in uvw1/F250W are found to correlate with the B-band light-curve shape parameter dm15(B), but with much larger scatter relative to the correlation in the broad-band B band (e.g., ~0.4 mag versus ~0.2 mag for those with 0.8 < dm15 < 1.7 mag). SN 2004dt is found as an outlier of this correlation (at > 3 sigma), being brighter than normal SNe Ia such as SN 2005cf by ~0.9 mag and ~2.0 mag in the uvw1/F250W and uvm2/F220W filters, respectively. We show that different progenitor metallicity or line-expansion velocities alone cannot explain such a large discrepancy. Viewing-angle effects, such as due to an asymmetric explosion, may have a significant influence on the flux emitted in the UV region. Detailed modeling is needed to disentangle and quantify the above effects.
Keywords
Cite
@article{arxiv.1110.5809,
title = {Evidence for Type Ia Supernova Diversity from Ultraviolet Observations with the Hubble Space Telescope},
author = {Xiaofeng Wang and Lifan Wang and Alexei V. Filippenko and Eddie Baron and Markus Kromer and Dennis Jack and Tianmeng Zhang and Greg Aldering and Pierre Antilogus and David Arnett and Dietrich Baade and Brian J. Barris and Stefano Benetti and Patrice Bouchet and Adam S. Burrows and Ramon Canal and Enrico Cappellaro and Raymond Carlberg and Elisa di Carlo and Peter Challis and Arlin Crotts and John I. Danziger and Massimo Della Valle and Michael Fink and Ryan J. Foley and Claes Fransson and Avishay Gal-Yam and Peter Garnavich and Chris L. Gerardy and Gerson Goldhaber and Mario Hamuy and Wolfgang Hillebrandt and Peter A. Hoeflich and Stephen T. Holland and Daniel E. Holz and John P. Hughes and David J. Jeffery and Saurabh W. Jha and Dan Kasen and Alexei M. Khokhlov and Robert P. Kirshner and Robert Knop and Cecilia Kozma and Kevin Krisciunas and Brian C. Lee and Bruno Leibundgut and Eric J. Lentz and Douglas C. Leonard and Walter H. G. Lewin and Weidong Li and Mario Livio and Peter Lundqvist and Dan Maoz and Thomas Matheson and Paolo Mazzali and Peter Meikle and Gajus Miknaitis and Peter Milne and Stefan Mochnacki and Ken'Ichi Nomoto and Peter E. Nugent and Elaine Oran and Nino Panagia and Saul Perlmutter and Mark M. Phillips and Philip Pinto and Dovi Poznanski and Christopher J. Pritchet and Martin Reinecke and Adam Riess and Pilar Ruiz-Lapuente and Richard Scalzo and Eric M. Schlegel and Brian Schmidt and James Siegrist and Alicia M. Soderberg and Jesper Sollerman and George Sonneborn and Anthony Spadafora and Jason Spyromilio and Richard A. Sramek and Sumner G. Starrfield and Louis G. Strolger and Nicholas B. Suntzeff and Rollin Thomas and John L. Tonry and Amedeo Tornambe and James W. Truran and Massimo Turatto and Michael Turner and Schuyler D. Van Dyk and Kurt Weiler and J. Craig Wheeler and Michael Wood-Vasey and Stan Woosley and Hitoshi Yamaoka},
journal= {arXiv preprint arXiv:1110.5809},
year = {2015}
}
Comments
17 pages, 13 figures, accepted by ApJ