J/MNRAS/426/2668 Soft X-ray emission of Type Ia SN progenitors (Nielsen+, 2012)
Upper limits on bolometric luminosities of 10 Type Ia supernova progenitors
from Chandra observations.
Nielsen M.T.B., Voss R., Nelemans G.
<Mon. Not. R. Astron. Soc., 426, 2668-2676 (2012)>
=2012MNRAS.426.2668N 2012MNRAS.426.2668N
ADC_Keywords: Supernovae ; X-ray sources
Keywords: binaries: close - binaries: symbiotic - circumstellar matter -
supernovae: general - white dwarfs - X-rays: binaries
Abstract:
We present an analysis of Chandra observations of the position of 10
nearby (<25Mpc) Type Ia supernovae, taken before the explosions. No
sources corresponding to progenitors were found in any of the
observations. We calculated upper limits on the bolometric
luminosities of the progenitors assuming blackbody X-ray spectra with
temperatures of 30-150eV. This is inspired by the fact that
luminous super-soft X-ray sources have been suggested as the direct
progenitors of Type Ia supernovae. The upper limits of two supernovae
in our sample are comparable to the luminosities of the brightest
observed super-soft sources, ruling out such sources as the
progenitors of these supernovae. In contrast to Liu et al.
(2012ApJ...749..141L 2012ApJ...749..141L), we find that for SN2011fe we can rule out
Eddington luminosity systems for blackbody temperatures as low as
40eV. Our findings are consistent with statistical studies comparing
the observed Type Ia supernova rate to the number of super-soft
sources or the integrated X-ray luminosity in external galaxies. This
suggests that either the progenitors of Type Ia supernovae are not
accreting, nuclear burning white dwarfs or that they do not look like
the classical super-soft sources, e.g. because they are obscured.
Description:
By searching the Chandra Data Archive, we found pre-explosion images
taken with the Advanced CCD Imaging Spectrometer (ACIS-S) at the
positions of 10 nearby (<25Mpc) SNe Ia. The SNe in question are
SN2002cv, SN2003cg, SN2004W, SN2006X, SN2006dd, SN2006mr, SN2007gi,
SN2007sr, SN2008fp and SN2011fe. No obvious sources were found on the
pre-explosion images for any of these SNe.
For SN2002cv, SN2003cg, SN2004W, SN2006X, SN2006dd, SN2006mr, SN2007gi
and SN2008fp, only a single pre-explosion Chandra image exists for
each of the SNe, and SN2006dd and SN2006mr are on the same image.
Several of these images have long (>30ks) exposure times. For
SN2007sr and SN2011fe, multiple pre-explosion Chandra images exist,
and these can be combined to give very long (several 100ks)
exposure times.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 74 11 Host galaxies, distances and total hydrogen
columns for each of the supernovae analysed
table2.dat 65 39 Chandra observations used in this study. All
observations are with the ACIS-S detector
table3.dat 118 11 Upper limit bolometric luminosities of nearby
(<25Mpc) SNe Ia with pre-explosion images
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See also:
B/sn : Asiago Supernova Catalogue (Barbon et al., 1999-)
B/chandra : The Chandra Archive Log (CXC, 1999-2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- SN Supernova name
7 A1 --- n_SN [*] SN 2011fe has 2 entries with 2 NH values
9- 19 A11 --- Gal Host galaxy name
22- 25 F4.1 Mpc Dist Distance
27- 34 E8.2 cm-2 NH Absorbing column density
36- 74 A39 --- r_NH Reference for NH
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 4 I4 --- ObsID Chandra observation number
6- 10 F5.2 ks ExpTime Exposure time
12- 13 I2 h RAh Pointing right ascension (J2000)
15- 16 I2 min RAm Pointing right ascension (J2000)
18- 22 F5.2 s RAs Pointing right ascension (J2000)
24 A1 --- DE- Pointing declination sign (J2000)
25- 26 I2 deg DEd Pointing declination (J2000)
28- 29 I2 arcmin DEm Pointing declination (J2000)
31- 35 F5.2 arcsec DEs Pointing declination (J2000)
37- 42 A6 --- SN SN covered
45- 54 A10 "YYYY-MM-DD" EDate SN explosion date
56- 65 A10 "YYYY-MM-DD" ODate Observation date
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- SN SN name
9- 10 I2 h RAh Right ascension (J2000)
12- 13 I2 min RAm Right ascension (J2000)
15- 19 F5.2 s RAs Right ascension (J2000)
21 A1 --- DE- Declination sign (J2000)
22- 23 I2 deg DEd Declination (J2000)
25- 26 I2 arcmin DEm Declination (J2000)
28- 32 F5.2 arcsec DEs Declination (J2000)
33- 38 F6.2 ks t.exp Chandra exposure time
39 A1 --- n_t.exp [b] Total exposure time is given for the
combined image (several observations)
41- 42 I2 ct Ct [0/44] Chandra counts (0.3-1keV)
in source region
44- 53 E10.6 s.cm2 Emap30 Value of exposure map at position at 30eV
55- 61 E7.3 10-7W Lbol30 Unabsorbed 3σ upper limit bolometric
luminosity at 30eV (erg/s)
63- 72 E10.6 s.cm2 Emap50 Value of exposure map at position at 50eV
74- 80 E7.3 10-7W Lbol50 Unabsorbed 3σ upper limit bolometric
luminosity at 50eV (erg/s)
82- 91 E10.6 s.cm2 Emap100 Value of exposure map at position at 100eV
93- 99 E7.3 10-7W Lbol100 Unabsorbed 3σ upper limit bolometric
luminosity at 100eV (erg/s)
101-110 E10.6 s.cm2 Emap150 Value of exposure map at position at 150eV
112-118 E7.3 10-7W Lbol150 Unabsorbed 3σ upper limit bolometric
luminosity at 150eV (erg/s)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 25-Apr-2013