J/ApJS/202/14 Diffuse OVII and OVIII emission from XMM (Henley+, 2012)
An XMM-Newton survey of the soft X-ray background.
II. An all-sky catalog of diffuse O VII and O VIII emission intensities.
Henley D.B., Shelton R.L.
<Astrophys. J. Suppl. Ser., 202, 14 (2012)>
=2012ApJS..202...14H 2012ApJS..202...14H
ADC_Keywords: X-ray sources ; Surveys ; Spectroscopy ; Interstellar medium
Keywords: Galaxy: halo - solar wind - surveys - X-rays: diffuse background -
X-rays: ISM
Abstract:
We present an all-sky catalog of diffuse OVII and OVIII line
intensities, extracted from archival XMM-Newton observations. This
catalog supersedes our previous catalog (Henley et al., 2010, Cat.
J/ApJS/187/388), which covered the sky between l=120° and
l=240°. We attempted to reduce the contamination from near-Earth
solar wind charge exchange (SWCX) emission by excluding times of high
solar wind proton flux from the data. Without this filtering, we were
able to extract measurements from 1868 observations. With this
filtering, nearly half of the observations became unusable, and only
1003 observations yielded measurements. The OVII and OVIII intensities
are typically ∼2-11 and ≲3 photons/cm2/s/sr (line unit, L.U.),
respectively, although much brighter intensities were also recorded.
Our data set includes 217 directions that have been observed multiple
times by XMM-Newton. The time variation of the intensities from such
directions may be used to constrain SWCX models.
Description:
We present a new catalog of soft X-ray background (SXRB) OVII and
OVIII intensities, extracted from 1880 archival XMM-Newton
observations. Our new analysis has some improvements over our previous
one (Paper I; Henley et al., 2010, Cat. J/ApJS/187/388), including the
use of more recent software and calibration data, the use of data from
the XMM-Newton Serendipitous Source Catalogue for point source
removal, and the estimation of the systematic errors on the oxygen
intensities.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 156 1880 OVII and OVIII line intensities (without proton
flux filtering)
table2.dat 158 1880 OVII and OVIII line intensities (with proton flux
filtering)
table4.dat 120 631 Oxygen line intensities from directions with
multiple observations
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See also:
B/xmm : XMM-Newton Observation Log (XMM-Newton Science Operation Center, 2012)
J/ApJS/187/388 : A XMM-Newton survey of the SXRB (Henley+, 2010)
J/A+A/508/1403 : Oxygen lines in solar granulation. II. (Pereira+, 2009)
http://xmmssc-www.star.le.ac.uk/Catalogue/2XMMi-DR3/ : XMM catalogue pages
Byte-by-byte Description of file: table[12].dat
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Bytes Format Units Label Explanations
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1- 10 I010 --- XMM XMM observation identifier
12- 21 A10 "YYYY/MM/DD" ObsDate Date of observation start
23- 29 F7.3 deg GLON Galactic longitude
31- 37 F7.3 deg GLAT Galactic latitude
40- 43 F4.1 ks texp1a ? MOS1 exposure time a (1)
44 A1 --- --- [,] (1)
45- 48 F4.1 ks texp1b ? MOS1 exposure time b (1)
49 A1 --- --- [,] (1)
50- 54 F5.1 ks texp1c ? MOS1 exposure time c (1)
56- 58 I3 arcmin2 Ome1a ? Solid angle of MOS1 detector a (1)(2)
59 A1 --- --- [,] (1)
60- 62 I3 arcmin2 Ome1b ? Solid angle of MOS1 detector b (1)(2)
63 A1 --- --- [,] (1)
64- 66 I3 arcmin2 Ome1c ? Solid angle of MOS1 detector c (1)(2)
69- 72 F4.1 ks texp2a ? MOS2 exposure time a (1)
73 A1 --- --- [,] (1)
74- 77 F4.1 ks texp2b ? MOS2 exposure time b (1)
78 A1 --- --- [,] (1)
79- 83 F5.1 ks texp2c ? MOS2 exposure time c (1)
85- 87 I3 arcmin2 Ome2a ? Solid angle of MOS2 detector a (1)(2)
88 A1 --- --- [,] (1)
89- 91 I3 arcmin2 Ome2b ? Solid angle of MOS2 detector b (1)(2)
92 A1 --- --- [,] (1)
93- 95 I3 arcmin2 Ome2c ? Solid angle of MOS2 detector c (1)(2)
97-101 F5.2 --- I7 ? Observed O VII intensity (3)
103-106 F4.2 --- E_I7 ? Upper limit uncertainty in I7 (4)
108-111 F4.2 --- e_I7 ? Lower limit uncertainty in I7 (4)
113-116 F4.2 --- e7 ? Estimated systematic error in I7
118-123 F6.4 keV E7 ? Photon energy (5)
125-129 F5.2 --- I8 ? Observed O VIII intensity (3)
131-134 F4.2 --- E_I8 ? Upper limit uncertainty in I8 (4)
136-139 F4.2 --- e_I8 ? Lower limit uncertainty in I8 (4)
141-145 F5.2 --- eI8 ? Estimated systematic error in I8
147-151 F5.2 10+4/m2/s <fSW> ? Average solar wind proton flux (6)
153-156 F4.2 --- Ratio ? Ratio of total to EPL flux (7)
158 A1 --- Filt [YN] Affected by filtering? (table 2 only)
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Note (1): If an observation had more than one usable exposure, the values for
each exposure are presented as a comma-separated list (a,b,c).
Note (2): From which the soft X-ray background (SXRB) spectrum was extracted.
Note (3): This is the observed intensity - it has not been subjected to any
deabsorption. Units are in line units, L.U., or photons/cm2/s/sr.
Note (4): These are 1σ statistical errors from the fitting calculated
with XSPEC's error command using χ2min+2.3 for two
interesting parameters.
Note (5): Of the δ-function used to model the OVII emission rounded to
the central energy of the 5eV wide RMF (redistribution matrix file)
bin in which the line lies (see Paper I; Henley et al., 2010, Cat.
J/ApJS/187/388).
Note (6): During the XMM-Newton observation, in unbits of 108m-2s-1.
These data are from OMNIWeb (http://omniweb.gsfc.nasa.gov/).
If there were no good solar wind data during the observation,
this field is blank.
Note (7): Model flux in 2-5keV band to Extragalactic Power-Law (EPM) flux.
We used this ratio as a measure of the contamination of the count-rate
due to soft protons impinging upon the detector (see text for details).
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Set Unique dataset number
5- 6 I2 --- Nobs Number of observations in Set
8- 17 I010 --- XMM XMM observation identifier
19- 20 I2 --- Set1 ? Paper 1 (Cat. J/ApJS/187/388) dataset number
22- 28 F7.3 deg GLON Galactic longitude
30- 36 F7.3 deg GLAT Galactic latitude
38- 42 F5.2 --- I7 Observed OVII intensity without proton flux
filtering (1)
44- 47 F4.2 --- E_I7 Upper limit uncertainty in I7 (2)
49- 52 F4.2 --- e_I7 Lower limit uncertainty in I7 (2)
54- 57 F4.2 --- eI7 Estimated systematic error in I7
59- 63 F5.2 --- I8 Observed OVIII intensity without proton flux
filtering (1)
65- 68 F4.2 --- E_I8 Upper limit uncertainty in I8 (2)
70- 73 F4.2 --- e_I8 Lower limit uncertainty in I8 (2)
75- 78 F4.2 --- eI8 Estimated systematic error in I8
80- 84 F5.2 --- I7Iw ? Observed OVII intensity with proton flux
filtering (1)
86- 89 F4.2 --- E_I7Iw ? Upper limit uncertainty in I7Iw (2)
91- 94 F4.2 --- e_I7Iw ? Lower limit uncertainty in I7Iw (2)
96- 99 F4.2 --- eI7Iw ? Estimated systematic error in I7Iw
101-105 F5.2 --- I8Iw ? Observed OVIII intensity with proton flux
filtering (1)
107-110 F4.2 --- E_I8Iw ? Upper limit uncertainty in I8Iw (2)
112-115 F4.2 --- e_I8Iw ? Lower limit uncertainty in I8Iw (2)
117-120 F4.2 --- eI8Iw ? Estimated systematic error in I8Iw
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Note (1): This is the observed intensity - it has not been subjected to any
deabsorption. Units are in line units, L.U., or photons/cm2/s/sr.
Note (2): These are 1σ statistical errors from the fitting calculated
with XSPEC's error command using χ2min+2.3 for two
interesting parameters.
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History:
From electronic version of the journal
References:
Henley & Shelton Paper I. 2010ApJS..187..388H 2010ApJS..187..388H Cat. J/ApJS/187/388
Henley & Shelton Paper III. 2013ApJ...773...92H 2013ApJ...773...92H Cat. J/ApJ/773/92
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 18-Oct-2012