PERSISTENT C II ABSORPTION IN THE NORMAL TYPE Ia SUPERNOVA 2002fk
We present well-sampled UBVRIJHK photometry of SN 2002fk starting 12 days before maximum light through 122 days after peak brightness, along with a series of 15 optical spectra from -4 to +95 days since maximum. Our observations show the presence of C II lines in the early-time spectra of SN 2002fk, expanding at 11,000 km s(-1) and persisting until 8 days past maximum light with a velocity of similar to 9000 km s(-1). SN 2002fk is characterized by a small velocity gradient of. (upsilon) over dotS(i II) = 26 km s(-1) day(-1), possibly caused by an off-center explosion with the ignition region oriented toward the observer. The connection between the viewing angle of an off-center explosion and the presence of C II in the early-time spectrum suggests that the observation of C II could be also due to a viewing angle effect. Adopting the Cepheid distance to NGC 1309 we provide the first H-0 value based on near-infrared (near-IR) measurements of a Type Ia supernova (SN) between 63.0 +/- 0.8 (+/- 3.4 systematic) and 66.7 +/- 1.0 (+/- 3.5 systematic) kms(-1) Mpc(-1), depending on the absolute magnitude/decline rate relationship adopted. It appears that the near-IR yields somewhat lower (6%-9%) H-0 values than the optical. It is essential to further examine this issue by (1) expanding the sample of high-quality near-IR light curves of SNe in the Hubble flow, and (2) increasing the number of nearby SNe with near-IR SN light curves and precise Cepheid distances, which affords the promise to deliver a more precise determination of H-0.
|Título según WOS:||PERSISTENT C II ABSORPTION IN THE NORMAL TYPE Ia SUPERNOVA 2002fk|
|Título según SCOPUS:||Persistent C II absorption in the normal type Ia supernova 2002fk|
|Título de la Revista:||ASTROPHYSICAL JOURNAL|
|Editorial:||UNIV CHICAGO PRESS|
|Fecha de publicación:||2014|
|Página de inicio:||89|