Spectroscopic Observations and Analysis of the Peculiar SN 1999aa

Details Spectroscopic Observations and Analysis of the Peculiar SN 1999aa Spectroscopic Observations and Analysis of the Peculiar SN 1999aa

2004-04-20

arxiv.org/abs/astro-ph/0404393v1

Astron.J. 128 (2004) 387-404

Astronomy and Astrophysics

Astrophysics

46 pages including 23 figures. Accepted for publication by AJ. For full-resolution figures see http://www.physto.se/~gabri/sn9

Scientific paper

10.1086/421747

We present an extensive new time-series of spectroscopic data of the peculiar SN 1999aa in NGC 2595. Our data set includes 25 optical spectra between -11 and +58 days with respect to B-band maximum light, providing an unusually complete time history. The early spectra resemble those of a SN 1991T-like object but with a relatively strong Ca H&K absorption feature. The first clear sign of Si II 6355, characteristic of Type Ia supernovae, is found at day -7 and its velocity remains constant up to at least the first month after B-band maximum light. The transition to normal-looking spectra is found to occur earlier than in SN 1991T suggesting SN 1999aa as a possible link between SN 1991T-like and Branch-normal supernovae. Comparing the observations with synthetic spectra, doubly ionized Fe, Si and Ni are identified at early epochs. These are characteristic of SN 1991T-like objects. Furthermore, in the day -11 spectrum, evidence is found for an absorption feature which could be identified as high velocity C II 6580 or H-alpha. At the same epoch C III 4648.8 at photospheric velocity is probably responsible for the absorption feature at 4500 A. High velocity Ca is found around maximum light together with Si II and Fe II confined in a narrow velocity window. Implied constraints on supernovae progenitor systems and explosion hydrodynamical models are briefly discussed.

Affiliated with

Also associated with

No associations

Rating

Spectroscopic Observations and Analysis of the Peculiar SN 1999aa does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Spectroscopic Observations and Analysis of the Peculiar SN 1999aa, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spectroscopic Observations and Analysis of the Peculiar SN 1999aa will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-55173