Rubina Kotak - Academia.edu (original) (raw)
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Homi Bhabha National Institute (HBNI, BARC, MUMBAI)
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Papers by Rubina Kotak
Astrophysical Journal, 2007
We present a new, detailed analysis of late-time mid-infrared observations of the Type II-P super... more We present a new, detailed analysis of late-time mid-infrared observations of the Type II-P supernova (SN) 2003gd. At about 16 months after the explosion, the mid-IR flux is consistent with emission from 4 ; 10 À5 M of newly condensed dust in the ejecta. At 22 months emission from pointlike sources close to the SN position was detected at 8 and 24 m. By 42 months the 24 m flux had faded. Considerations of luminosity and source size rule out the ejecta of SN 2003gd as the main origin of the emission at 22 months. A possible alternative explanation for the emission at this later epoch is an IR echo from preexisting circumstellar or interstellar dust. We conclude that, contrary to the claim of Sugerman and coworkers, the mid-IR emission from SN 2003gd does not support the presence of 0.02 M of newly formed dust in the ejecta. There is, as yet, no direct evidence that core-collapse supernovae are major dust factories. Subject headingg s: supernovae: general -supernovae: individual (SN 2003gd)
ABSTRACT CBET 3172 available at Central Bureau for Astronomical Telegrams.
Monthly Notices of the Royal Astronomical Society, 2013
We present the one-year long observing campaign of SN 2012A which exploded in the nearby (9.8 Mpc... more We present the one-year long observing campaign of SN 2012A which exploded in the nearby (9.8 Mpc) irregular galaxy NGC 3239. The photometric evolution is that of a normal type IIP supernova, but the plateau is shorter and the luminosity not as constant as in other supernovae of this type. The absolute maximum magnitude, with M B = −16.23 ± 0.16 mag, is close to the average for SN IIP. Thanks also to the strong U V flux in the early phase, SN 2012A reached a peak luminosity of about 2 × 10 42 erg s −1 , which is brighter than those of other SNe with a similar 56 Ni mass. The latter was estimated from the luminosity in the exponential tail of the light curve and found to be M( 56 Ni) = 0.011 ± 0.004 M ⊙ , which is intermediate between standard and faint SN IIP.
Astrophysical Journal, 2007
We present a new, detailed analysis of late-time mid-infrared observations of the Type II-P super... more We present a new, detailed analysis of late-time mid-infrared observations of the Type II-P supernova (SN) 2003gd. At about 16 months after the explosion, the mid-IR flux is consistent with emission from 4 ; 10 À5 M of newly condensed dust in the ejecta. At 22 months emission from pointlike sources close to the SN position was detected at 8 and 24 m. By 42 months the 24 m flux had faded. Considerations of luminosity and source size rule out the ejecta of SN 2003gd as the main origin of the emission at 22 months. A possible alternative explanation for the emission at this later epoch is an IR echo from preexisting circumstellar or interstellar dust. We conclude that, contrary to the claim of Sugerman and coworkers, the mid-IR emission from SN 2003gd does not support the presence of 0.02 M of newly formed dust in the ejecta. There is, as yet, no direct evidence that core-collapse supernovae are major dust factories. Subject headingg s: supernovae: general -supernovae: individual (SN 2003gd)
ABSTRACT CBET 3172 available at Central Bureau for Astronomical Telegrams.
Monthly Notices of the Royal Astronomical Society, 2013
We present the one-year long observing campaign of SN 2012A which exploded in the nearby (9.8 Mpc... more We present the one-year long observing campaign of SN 2012A which exploded in the nearby (9.8 Mpc) irregular galaxy NGC 3239. The photometric evolution is that of a normal type IIP supernova, but the plateau is shorter and the luminosity not as constant as in other supernovae of this type. The absolute maximum magnitude, with M B = −16.23 ± 0.16 mag, is close to the average for SN IIP. Thanks also to the strong U V flux in the early phase, SN 2012A reached a peak luminosity of about 2 × 10 42 erg s −1 , which is brighter than those of other SNe with a similar 56 Ni mass. The latter was estimated from the luminosity in the exponential tail of the light curve and found to be M( 56 Ni) = 0.011 ± 0.004 M ⊙ , which is intermediate between standard and faint SN IIP.