Chandra X-ray observations of SN2014J
ATel #5851; R. Margutti, A. Soderberg, A. Kamble, A. Zauderer, D. Milisavljevic, J. Parrent (Harvard), L. Chomiuk (Michigan State)
on 4 Feb 2014; 22:32 UT
Credential Certification: Raffaella Margutti (email@example.com)
Subjects: X-ray, Supernovae
Referred to by ATel #: 5880
We observed the type Ia SN2014J (CBET #3792) with the Chandra X-ray Observatory (PI Margutti) beginning February 3, 20:10:39 UT, for a total exposure time of 47 ks. No point source is detected at the updated position of the SN (Smith Atel #5821), with a preliminary 3-sigma upper limit of 2d-4 c/s (0.3-10 keV energy band). For a power-law spectrum with photon index Gamma=2 this translates into an absorbed flux limit < 3.5d-15 erg/s/cm2.
The unabsorbed flux limit depends on the neutral hydrogen column density in the direction of SN2014J. Optical spectra and photometry of SN2014J point to the presence of substantial local reddening (corresponding to E(B-V)~ 1-1.5 mag, Cox Atel #5797, Maksym Atel #5798, Nielsen Atel #5799, Kotak Atel #5816, Altavilla Atel #5818, Patat Atel # 5830, Rihardson Atel #5840), indicating that local absorption dominates over the Galactic contribution. The Galactic neutral hydrogen column density in the direction of the transient is 5.1d20 cm-2 (Kalberla et al., 2005). We calculate our preliminary flux limits for a fiducial range of intrinsic hydrogen column density values: 5d21 cm-2< NH_int < 1d22 cm-2.
For an intrinsic hydrogen column density NH_int=5d21 cm-2 (1d22 cm-2) the unabsorbed flux limit is 1.4d-14 erg/s/cm2 (2.4d-14erg/s/cm2) in the 0.3-10 keV energy range, corresponding to L< 2.1d37 erg/s (L< 3.5d37 erg/s) at the distance of M82 (3.5 Mpc, Karachentsev & Kashibadze, 2006).
We thank the Chandra team for their excellent support in scheduling our observations.