arXiv subjects

M. Stritzinger

Publications and source records attributed to M. Stritzinger.

76 records · Page 5Linked to original sources

arXiv2004

Photometric Observations of the Type Ia SN 2002er in UGC 10743

Extensive light and colour curves for the Type Ia supernova SN 2002er are presented as part of the European Supernova Collaboration. We have collected UBVRI photometry from ten different telescopes covering the phases from 7 days before until 619 days after maximum light. Corrections for the different instrumental systems and the non-thermal spectrum of the supernova (S-corrections) have been applied. With the densely sampled light curves we can make detailed comparisons to other well-observed objects. SN 2002er most closely resembles SN 1996X after maximum, but clearly shows a different colour evolution before peak light and a stronger shoulder in V and R bands compared to other well-observed SNe Ia. In particular, the rise time appears to be longer than what is expected from rise-time vs.decline-rate relation. We use several methods to determine the reddening towards SN 2002er based on the colour evolution at near peak and at late phases. The uvoir (bolometric) light curve shows great similarity with SN 1996X, but also indications of a higher luminosity, longer rise time and a more pronounced shoulder 25 days past maximum. The interpretation of the light curves was done with two independent light curve codes. Both find that given the luminosity of SN 2002er the 56Ni mass exceeds 0.6 Msun with prefered values near 0.7 Msun. Uncertainties in the exact distance to SN 2002er are the most serious limitation of this measurement. The light curve modelling also indicates a high level of mixing of the nickel in the explosion of SN 2002er.

astro-ph↗

arXiv2004

ESC Observations of SN 2002er around Maximum Light

We present preliminary results of the observational campaign on SN 2002er carried out by the European Supernova Collaboration (ESC). For this supernova the optical coverage from epochs -11 days to +50 days is excellent, both in imaging and spectroscopy. The extinction deduced from the photometry is E(B-V)=0.35, while Deltam15=1.31. In general SN 2002er behaves like a "normal" type Ia supernova, very similar to SN 1996X.

astro-ph↗

arXiv2002

Optical Photometry of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex in IC 5179

We present UBVRIz lightcurves of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex, both located in the galaxy IC 5179. SN 1999ee has an extremely well sampled lightcurve spanning from 10 days before Bmax through 53 days after peak. Near maximum we find systematic differences ~0.05 mag in photometry measured with two different telescopes, even though the photometry is reduced to the same local standards around the supernova using the specific color terms for each instrumental system. We use models for our bandpasses and spectrophotometry of SN 1999ee to derive magnitude corrections (S-corrections) and remedy this problem. This exercise demonstrates the need of accurately characterizing the instrumental system before great photometric accuracies of Type Ia supernovae can be claimed. It also shows that this effect can have important astrophysical consequences since a small systematic shift of 0.02 mag in the B-V color can introduce a 0.08 mag error in the extinction corrected peak B magnitudes of a supernova and thus lead to biased cosmological parameters. The data for the Type Ib/c SN 1999ex present us with the first ever observed shock breakout of a supernova of this class. These observations show that shock breakout occurred 18 days before Bmax and support the idea that Type Ib/c supernovae are due to core collapse of massive stars rather than thermonuclear disruption of white dwarfs.

astro-ph↗

arXiv1999

A NICMOS Survey of Early-Type Galaxy Centers: The Relation Between Core Properties, Gas and Dust Content and Environment

We present a NICMOS 1.6 micron imaging isophotal study of 27 early-type galaxies. Our selected sample is not as biased against dusty galaxies as the visible WFPC samples observed with HST. Core galaxies have reduced ellipticity and boxiness near and within their core or break radius. This supports a core formation mechanism which mixes or scatters stars such as scattering caused by a binary black hole. We find no correlation between core properties and dust mass or X-ray luminosity, suggesting that processes determining the current gas content (e.g., such as minor mergers and cooling flows) are unrelated to processes occurring during core formation. Core galaxies exist in a variety of environments ranging from poor groups to large clusters. A combined sample suggests that galaxy groups may harbor more luminous power law galaxies than clusters such as Virgo and Fornax.

astro-ph↗