J/ApJ/753/22 Swift/UVOT observations of SN 2011fe (Brown+, 2012)
A Swift look at SN 2011fe: the earliest ultraviolet observations of a
type Ia supernova.
Brown P.J., Dawson K.S., de Pasquale M., Gronwall C., Holland S.,
Immler S., Kuin P., Mazzali P., Milne P., Oates S., Siegel M.
<Astrophys. J., 753, 22 (2012)>
=2012ApJ...753...22B 2012ApJ...753...22B
ADC_Keywords: Supernovae ; Photometry, ultraviolet ; Photometry, uvby
Keywords: galaxies: distances and redshifts; supernovae: general;
ultraviolet: general
Abstract:
We present the earliest ultraviolet (UV) observations of the bright
Type Ia supernova SN 2011fe/PTF11kly in the nearby galaxy M101 at a
distance of only 6.4 Mpc. It was discovered shortly after explosion by
the Palomar Transient Factory and first observed by Swift/UVOT about a
day after explosion. The early UV light is well defined, with ∼20 data
points per filter in the five days after explosion. These early and
well-sampled UV observations form new template light curves for
comparison with observations of other SNe Ia at low and high redshift.
We report fits from semiempirical models of the explosion and find the
time evolution of the early UV flux to be well fitted by the
superposition of two parabolic curves. Finally, we use the early UV
flux measurements to examine a possible shock interaction with a
non-degenerate companion. From models predicting the measurable shock
emission, we find that even a solar mass companion at a distance of a
few solar radii is unlikely at more than 95% confidence.
Description:
SN 2011fe, also known as PTF11kly, was discovered in M101 at a
magnitude g=17.2, classified as a probable young Ia, and promptly
announced by the Palomar Transient Factory (PTF) on 2011 August 24.
X-ray and UV observations were promptly requested from the Swift
observatory, and observations began August 24.9. Swift's UVOT utilized
the six broadband filters with the following central wavelengths
(λc) and FWHM in angstroms: uvw2 (λc=1928;
FWHM=657), uvm2 (λc=2246; FWHM=498), uvw1 (λc=2600;
FWHM=693), u (λc=3465; FWHM=785), b (λc=4392;
FWHM=975), and v (λc=5468; FWHM=769).
Following the announcement of the discovery of SN 2011fe, we requested
daily Swift observations to monitor its UV and optical behavior. A
multi-filter image of SN 2011fe and its host galaxy is displayed in
Figure 1.
Objects:
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RA (2000) DE Designation(s)
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14 03 05.73 +54 16 25.2 SN 2011fe = PTF 11kly
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 63 1032 SN2011fe UVOT magnitudes, count rates and fluxes
table2.dat 17 1956 UV light curve templates
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
J/A+A/554/A27 : 2011fe spectrophotometric time series (Pereira+, 2013)
J/MNRAS/426/2668 : X-ray emission of Type Ia SN progenitors (Nielsen+, 2012)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- Filt Filter used in observation (u, b, v, uvm2,
uvw1 or uvw2)
6- 15 F10.4 d MJD Modified Julian Date of observation
17- 21 F5.2 mag mag [10/19]? Swift/UVOT observed magnitude in Filt
23- 26 F4.2 mag e_mag [0.04/0.4]? Uncertainty in mag
28- 32 F5.2 mag B_mag [13.3/18.8] The 3σ upper limit
34- 39 F6.2 ct/s CRate [0.01/683] Swift/UVOT count rate
41- 45 F5.2 ct/s e_CRate [0.05/23] Uncertainty in CRate
47- 54 E8.2 mW/m2 Flux Observed flux; erg/s/cm2
56- 63 E8.2 mW/m2 e_Flux Uncertainty in Flux; erg/s/cm2
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 4 A4 --- Filt Filter used in observation (uvm2, uvw1 or uvw2)
6- 10 F5.1 d Epoch [-15/50] Epoch from maximum (1)
12- 17 F6.3 mag mag [0/8.3] Template magnitude in Filter (1)
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Note (1): The epochs and magnitudes are given with respect to the peak time
and magnitude in that filter.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 07-Feb-2014