J/MNRAS/311/741 SMC emission-line objects (Murphy+, 2000)
Catalogue of candidate emission-line objects in the Small Magellanic Cloud.
Murphy M.T., Bessell M.S.
<Mon. Not. R. Astron. Soc. 311, 741 (2000)>
=2000MNRAS.311..741M 2000MNRAS.311..741M
ADC_Keywords: Magellanic Clouds ; Stars, emission ; Planetary nebulae
Keywords: methods: observational - catalogues - astrometry -
planetary nebulae: general - Magellanic Clouds
Abstract:
Hα and [OIII] narrow-band, wide-field (7x7deg2), CCD images of
the Small Magellanic Cloud were compared, and a catalogue of candidate
planetary nebulae and Hα emission-line stars was compiled. The
catalogue contains 131 planetary nebulae candidates, 23 of which are
already known to be or are probable planetary nebulae or very low
excitation objects. Also, 218 emission-line candidates have been
identified, with 113 already known. Our catalogue therefore provides a
useful supplement to those of Meyssonnier & Azzopardi (1993, Cat.
J/A+AS/102/451) and Sanduleak, MacConnell & Davis Phillip
(1978PASP...90..621S 1978PASP...90..621S). Further observations are required to confirm
the identity of the unknown objects.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 52 318 Catalogue of objects with accurate positions
(±12 arcsec). Unless otherwise stated in the
description, all objects are candidates for PN.
table2.dat 52 54 Objects that only had an estimated pixel number
assigned to them (i.e. no Gaussian fit was
performed in position finding). A 15arcsec error
(∼3σ) in position should be allowed for
these objects unless otherwise marked.
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See also:
V/13 : Probable Members of the SMC (Azzopardi+ 1975, 1979)
J/A+AS/102/451 : Emission-line stars and PNe in the SMC (Meyssonnier+ 1993)
Byte-by-byte Description of file: table?.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- [MB2000] [1/372] Sequential number
6- 19 A14 --- Descrp Description (1)
21- 22 I2 h RAh Right ascension (J2000)
24- 25 I2 min RAm Right ascension (J2000)
27- 30 F4.1 s RAs Right ascension (J2000)
32 A1 --- DE- Declination sign (J2000)
33- 34 I2 deg DEd Declination (J2000)
36- 37 I2 arcmin DEm Declination (J2000)
39- 40 I2 arcsec DEs Declination (J2000)
42- 46 F5.2 mag GH ? Relative magnitude in the Hα band (2)
48- 52 F5.2 mag GO ? Relative magnitude in the [OIII] band (2)
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Note (1): Description:
G - A good candidate for a planetary nebula. The object had a
Gaussian-like profile and had significant flux in all frames.
Em* - Emission-line star. This represents a candidate for an Hα
emission-line star. These objects were not identified in MA93,
Meyssonnier & Assopardi, 1993, Cat. J/A+AS/102/451.
SMP xx - A known emission-line star. These objects lay outside the
survey range of MA93. We therefore use the co-ordinates in the
SMP78 catalogue. If a question mark (?) is appended to the
identifier then the coordinates are different by slightly more
than 12 arcsec from the known J2000 coordinates. Thus, some
uncertainty exists as to whether the identification is correct.
-xxxx- - Indicates that the object is identified in MA93 J/A+AS/102/451
as a PN with
the identifier xxxx and was not identified in SMP78.
[MA93] xxxx - A known emission-line star identified in MA93 (J/A+AS/102/451)
and numbered accordingly. A question mark (?) indicates the
same uncertainty as described for SMP xx, Sanduleak et al.,
1978PASP...90..621S 1978PASP...90..621S.
B - Bright region. The object appeared in a bright region of the
frame and so should be treated with some caution. May be
specified for a particular filter.
CCD - Bad CCD line or fault in CCD. This means that the object lies
close to a CCD fault in the images.
Dp - Different positions. This indicates that the centroids in the
Hα and [OIII] images were ∼1 pixel apart. These should be
treated as suspect.
F - Faint. This means that the object had low peak pixel value
compared to the background. A filter may be specified if the
object was only faint in one filter.
I - Irregular shape. The object did not have a Gaussian-like profile.
May be specified for a particular filter.
L - Large. The object is more than 2.5 pixels FWHM. This means that a
large area may have to be searched in subsequent observations
in order to find the emission object. Indeed, there may be
several emission objects around the given co-ordinate.
May be specified for a particular filter. A variation on this
description is `L region', meaning that the given coordinate is
the centroid of an area (at least 5 pixels FWHM) where many
emission objects may be located. Usually, this is also a
`bright' region.
S - Possibly a star. It was not clear from the images whether this
object is a star or not, due to the problems outlined in
Section 4.1 of the paper.
Sm - Small. This means that the object is contained within just one
pixel. May be specified for a particular filter.
Sp - Spread out. The object is reasonably faint and has a large FWHM
(usually >2 pixels). May be specified for a particular filter.
Sus. - The object in question had some feature that made it seem
unlikely that there was a genuine object at the given position.
A particular frame may be specified.
15" or 25" - A 15- or 25-arcsec error should be allowed for the RA and Dec.
Note (2): Magnitudes relative to continuum:
GH = m(Hα) - m(H(continuum)), error estimated to ±0.3mag
GO = m([OIII]) - m(V), error estimated to ±0.5mag
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History: Prepared via OCR at CDS.
* 27-Aug-2003: 34 errors detected in the OCR, corrected in table2
(End) James Marcout, Patricia Bauer [CDS] 31-May-2000