J/ApJ/805/74 SN2014J Swift/UVOT light curves (Brown+, 2015)
Swift ultraviolet observations of supernova 2014J in M82:
large extinction from interstellar dust.
Brown P.J., Smitka M.T., Wang L., Breeveld A., de Pasquale M.,
Hartmann D.H., Krisciunas K., Kuin N.P., Milne P.A., Page M., Siegel M.
<Astrophys. J., 805, 74 (2015)>
=2015ApJ...805...74B 2015ApJ...805...74B
ADC_Keywords: Photometry, UBV ; Photometry, ultraviolet ; Supernovae
Keywords: dust, extinction; supernovae: general;
supernovae: individual: (SN2014J, SN2011fe, SN2012fr)
Abstract:
We present optical and ultraviolet (UV) photometry and spectra of the
very nearby and highly reddened supernova (SN) 2014J in M82 obtained
with the Swift Ultra-Violet/Optical Telescope (UVOT). Comparison of
the UVOT grism spectra of SN 2014J with Hubble Space Telescope
observations of SN2011fe or UVOT grism spectra of SN 2012fr are
consistent with an extinction law with a low value of RV∼1.4. The
high reddening causes the detected photon distribution in the
broadband UV filters to have a much longer effective wavelength than
for an unreddened SN. The light curve evolution is consistent with
this shift and does not show a flattening due to photons being
scattered back into the line of sight (LOS). The light curve shapes
and color evolution are inconsistent with a contribution scattered
into the LOS by circumstellar dust. We conclude that most or all of
the high reddening must come from interstellar dust. We show that even
for a single dust composition, there is not a unique reddening law
caused by circumstellar scattering. Rather, when considering
scattering from a time-variable source, we confirm earlier studies
that the reddening law is a function of the dust geometry, column
density, and epoch. We also show how an assumed geometry of dust as a
foreground sheet in mixed stellar/dust systems will lead to a higher
inferred RV. Rather than assuming the dust around SNe is peculiar,
SNe may be useful probes of the interstellar reddening laws in other
galaxies.
Description:
The Swift satellite started observing SN 2014J in M82 at 2014 January
22.43 UT. Photometry observations were made on a roughly daily basis
between January 22 and February 25 and then continuing with a lower
cadence until April 10. Observations with the UVOT's UV grism were
made at seven epochs before and around maximum light. See section 2
for further details.
Objects:
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RA (ICRS) DE Designation(s)
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09 55 42.12 +69 40 25.9 SN2014J = PSN J09554214+6940260
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 65 336 SN2014J Swift/UVOT photometry
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/ApJ/799/105 : KELT light curve of the M82 SN 2014J (Siverd+, 2015)
J/other/NewA/20.30 : BVRI light curves of 3 SN (Munari+, 2013)
J/ApJ/742/89 : Relations between spectra and colors of SNe Ia (Foley+, 2011)
J/ApJ/721/1608 : Absolute UV magnitudes of type Ia SNe (Brown+, 2010)
J/AJ/139/120 : Low-redshift Type-Ia supernovae (Folatelli+, 2010)
J/ApJS/185/32 : First-year SDSS-II SN results (Kessler+, 2009)
J/ApJ/700/1097 : Light curve parameters of SN Ia (Hicken+, 2009)
J/ApJ/699/L139 : Spectral parameters of SNe Ia (Wang+, 2009)
J/AJ/137/4517 : UVOT light curves of supernovae (Brown+, 2009)
J/ApJ/645/488 : SN type Ia luminosities (Wang+, 2006)
http://people.physics.tamu.edu/pbrown/SwiftSN/swift_sn.html : Swift SNe
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- SN [SN2014J] Supernova identifier (SN2014J)
9- 12 A4 --- Filt Swift/UVOT filter (U, B, V, UVM2, UVW1 or UVW2)
14- 23 F10.4 d MJD Modified Julian Date of observation
25- 30 F6.3 mag mag [10.7/21.2]? Observed Vega magnitude in Filt
32- 36 F5.3 mag e_mag [0.02/0.4]? Uncertainty in mag
38- 43 F6.3 mag maglim [15.8/21.4] Magnitude limit in Filt
45- 50 F6.3 mag satlim [10.5/12] Saturation limit in Filt
52- 58 F7.3 ct/s CRate [-0.02/737] Count rate in Filt
60- 65 F6.3 ct/s e_CRate [0.006/20.1] Uncertainty in CRate
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 07-Sep-2015