NASA/IPAC EXTRAGALACTIC DATABASE
Date and Time of the Query: 2019-05-22 T06:45:17 PDT
Help | Comment | NED Home

For refcode 2005AJ....130.2278G:
Retrieve 62 NED objects in this reference.
Please click here for ADS abstract

NED Abstract

Copyright by American Astronomical Society. Reproduced by permission
2005AJ....130.2278G Spectroscopic Observations and Analysis of the Unusual Type Ia SN 1999ac G. Garavini, G. Aldering, A. Amadon, R. Amanullah, P. Astier, C. Balland, G. Blanc, A. Conley, T. Dahlen, S. E. Deustua, R. Ellis, S. Fabbro, V. Fadeyev, X. Fan, G. Folatelli, B. Frye, E. L. Gates, R. Gibbons, G. Goldhaber, B. Goldman, A. Goobar, D. E. Groom, J. Haissinski, D. Hardin, I. Hook, D. A. Howell, S. Kent, A. G. Kim, R. A. Knop, M. Kowalski, N. Kuznetsova, B. C. Lee, C. Lidman, J. Mendez, G. J. Miller, M. Moniez, M. Mouchet, A. Mourao, H. Newberg, S. Nobili, P. E. Nugent, R. Pain, O. Perdereau, S. Perlmutter, R. Quimby, N. Regnault, J. Rich, G. T. Richards, P. Ruiz-Lapuente, B. E. Schaefer, K. Schahmaneche, E. Smith, A. L. Spadafora, V. Stanishev, R. C. Thomas, N. A. Walton, L. Wang, W. M. Wood-Vasey, and (The Supernova Cosmology Project) Abstract. We present optical spectra of the peculiar Type Ia supernova (SN Ia) 1999ac. The data extend from -15 to +42 days with respect to B-band maximum and reveal an event that is unusual in several respects. Prior to B-band maximum, the spectra resemble those of SN 1999aa, a slowly declining event, but possess stronger Si II and Ca II signatures (more characteristic of a spectroscopically normal SN). Spectra after the B-band maximum appear more normal. The expansion velocities inferred from the iron lines appear to be lower than average, whereas the expansion velocity inferred from calcium H and K are higher than average. The expansion velocities inferred from Si II are among the slowest ever observed, although SN 1999ac is not particularly dim. The analysis of the parameters v_10_(Si II), R(Si II), v^dot^, and {DELTA}m_15_ further underlines the unique characteristics of SN 1999ac. We find convincing evidence of C II {lambda}6580 in the day -15 spectrum with ejection velocity v>16,000 km s^-1^, but this signature disappears by day -9. This rapid evolution at early times highlights the importance of extremely early-time spectroscopy. Key words: Stars: Supernovae: General, supernovae: individual (SN 1999ac)
Retrieve 62 NED objects in this reference.
Please click here for ADS abstract

Back to NED Home