J/MNRAS/440/1080 Calibration of Hα fluxes in SHS (Frew+, 2014)
Flux calibration of the AAO/UKST SuperCOSMOS Hα Survey.
Frew D.J., Bojicic I.S., Parker Q.A., Pierce M.J., Gunawardhana M.L.P.,
Reid W.A.
<Mon. Not. R. Astron. Soc., 440, 1080-1094 (2014)>
=2014MNRAS.440.1080F 2014MNRAS.440.1080F
ADC_Keywords: Surveys ; Planetary nebulae ; H II regions
Keywords: techniques: photometric - astronomical data bases: miscellaneous -
ISM: general - HII regions - planetary nebulae: general -
ISM: supernova remnants
Abstract:
The AAO/UKST SuperCOSMOS Hα Survey (SHS) was, when completed in
2003, a powerful addition to extant wide-field surveys. The
combination of areal coverage, spatial resolution and sensitivity in a
narrow imaging band, still marks it out today as an excellent resource
for the astronomical community. The 233 separate fields are available
online in digital form, with each field covering 25deg2. The SHS has
been the motivation for equivalent surveys in the north, and new
digital Hα surveys now beginning in the south such as VPHAS+. It
has been the foundation of many important discovery projects with the
Macquarie/AAO/Strasbourg Hα planetary nebula project being a
particularly successful example. However, the full potential of the
SHS has been hampered by lack of a clear route to acceptable flux
calibration from the base photographic data. We have determined the
calibration factors for 170 individual SHS fields, and present a
direct pathway to the measurement of integrated Hα fluxes and
surface brightnesses for resolved nebulae detected in the SHS. We also
include a catalogue of integrated Hα fluxes for >100 planetary
and other nebulae measured from the SHS, and use these data to show
that fluxes, accurate to ±0.10-0.14dex (∼25-35%), can be obtained
from these fields. For the remaining 63 fields, a mean calibration
factor of 12.0 counts/pixel/R can be used, allowing the determination
of reasonable integrated fluxes accurate to better than ±0.2dex
(∼50%). We outline the procedures involved and the caveats that need
to be appreciated in achieving such flux measurements. This paper
forms a handy reference source that will significantly increase the
scientific utility of the SHS.
Description:
In this paper we have completely redone the SHS calibration process
afresh, by selecting data from the unvignetted central regions (see
Fig. 2) of all 233 SHS fields (cf. Paper I, Parker et al.,
2005MNRAS.362..689P 2005MNRAS.362..689P).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 41 233 Data summary for all 233 SHS survey fields
table2.dat 83 102 A comparison of our SHS Hα fluxes for over
100 PNe and other nebulae with independent
integrated Hα fluxes taken from the literature
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See also:
J/ApJ/711/619 : α-element abundances in galactic PNe (Milingo+, 2010)
J/MNRAS/431/2 : Hα fluxes of Galactic planetary nebulae (Frew+, 2013)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- --- [HAL]
4- 7 I04 --- Field [67/1334] Field number in HAL survey
9- 12 F4.2 --- SF [0.4/1.6]?=- Continuum-subtraction scaling factor
14 A1 --- --- [(]
15- 18 F4.1 --- CF [6/21.4] Calibration factor,
in photons/pix/Rayleigh (1)
19 A1 --- --- [)] ) when fixed value (12.0)
21 I1 --- Qual [1/3] Quality rank (1=best)
23- 41 A19 --- Com Comments (R=Rayleigh unit) (1)
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Note (1): the Rayleigh (R) corresponds to a flux of 106 photons per cm2
and per second, in any direction, i.e. 1Rayleigh=106/4πph/cm2/s/sr.
Note there are 63 fields with no calibration factors determined (usually
due to poor dynamic range or high chemical fog, or both). A default value
of 12.0±3.0ct/pix/R can be used for these fields, as explained in the text.
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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- 17 A17 --- Name Planetary Nebula Name
19- 24 F6.2 [mW/m2] logFHal Hα flux from literature
26- 29 F4.2 [mW/m2] e_logFHal rms uncertainty on logFHal
31- 42 A12 --- r_logFHal Reference for logFHal (1)
44- 49 F6.2 [mW/m2] logFHa SHS Hα flux
51- 54 F4.2 [mW/m2] e_logFHa rms uncertainty on logFHa
56- 58 A3 --- --- [HAL]
59- 62 I04 --- Field [67/1334] Field number in HAL survey
64- 83 A20 --- Rem Remarks
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Note (1): Reference codes as follows:
ASTR91 = Acker et al. (1991A&AS...90...89A 1991A&AS...90...89A)
B03 = Boumis et al. (2003MNRAS.339..735B 2003MNRAS.339..735B)
B06 = Boumis et al. (2006MNRAS.367.1551B 2006MNRAS.367.1551B)
BDF99 = Beaulieu et al. (1999ApJ...515..610B 1999ApJ...515..610B, Cat. J/ApJ/515/610)
DB96 = Duerbeck & Benetti (1996ApJ...468L.111D 1996ApJ...468L.111D)
FBP13 = Frew et al. (2013MNRAS.431....2F 2013MNRAS.431....2F, Cat. J/MNRAS/431/2)
FBP13b = Frew et al. (2014MNRAS.440.1345F 2014MNRAS.440.1345F)
H94 = Hutsemekers (1994A&A...281L..81H 1994A&A...281L..81H)
HDM98 = Hua, Dopita & Martinis (1998A&AS..133..361H 1998A&AS..133..361H)
JaSt04 = Jacoby & Van de Steene (2004A&A...419..563J 2004A&A...419..563J, Cat. J/A+A/419/563)
KH93 = Kistiakowsky & Helfand (1993AJ....105.2199K 1993AJ....105.2199K)
M06 = Madsen et al. (2006ApJ...652..401M 2006ApJ...652..401M)
P99 = Pollacco (1999MNRAS.304..127P 1999MNRAS.304..127P)
PC12 = Parker et al. (2012MNRAS.427.3016P 2012MNRAS.427.3016P)
PC12a = Parker et al. (2012MNRAS.427.3016P 2012MNRAS.427.3016P). Fluxes revised using new
calibration factors from this work.
PFM11 = Parker et al. (q2011MNRAS.413.1835P)
RZ04 = Ruffle et al. (2004MNRAS.353..796R 2004MNRAS.353..796R)
S87 = Stahl (1987A&A...182..229S 1987A&A...182..229S)
SK89 = Shaw & Kaler (1989ApJS...69..495S 1989ApJS...69..495S)
WKG97 = Weinberger et al. (1997A&A...323..963W 1997A&A...323..963W)
XPPT = Xilouris et al. (1996A&A...310..603X 1996A&A...310..603X)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 26-Jan-2015