J/MNRAS/384/1277 Hα emission line sources from IPHAS (Witham+, 2008)
The IPHAS catalogue of Hα emission-line sources in the northern
Galactic plane.
Witham A.R., Knigge C., Drew J.E., Greimel R., Steeghs D., Gansicke B.T.,
Groot P.J., Mampaso A.
<Mon. Not. R. Astron. Soc. 384, 1277 (2008)>
=2008MNRAS.384.1277W 2008MNRAS.384.1277W
ADC_Keywords: Stars, emission ; Galactic plane ; Photometry, CCD ;
Photometry, H-alpha
Keywords: surveys - catalogues - stars: emission-line, Be -
Galaxy: stellar content
Abstract:
We present the first catalogue of point-source Hα emission line
objects selected from the INT/WFC Photometric Hα Survey of the
Northern Galactic Plane (IPHAS). In total, our catalogue contains 4853
point sources that exhibit strong photometric evidence for Hα
emission. The catalogue is a conservative subset of the emitters
present in IPHAS and it is likely that there are many more Hα
emitters present in the area of the Galactic Plane that IPHAS
observes. Our selection criteria are designed to be conservative
(rather than complete) in order to avoid a significant number of false
positives in the catalogue. In line with this, we find that of the
∼300 catalogue sources for which we have preliminary spectroscopic
follow-up observations, more than 95% are confirmed as genuine
emission-line sources.
Description:
We present IPHAS positions and photometry for 4853 sources selected as
having a Hα excess from the photometry. The catalogue covers the
magnitude range 13≤r'≤19.5mag, and includes sources in the northern
hemisphere in the galactic latitude range -5<b<5°. The data from
which the catalogue is derived come from IPHAS observations obtained
from September 2003 to January 2007 and represents ∼1500deg2 (80%)
of the ultimate survey area.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
emitters.dat 87 4853 Positions and photometry for 4853 sources
(table2 of the paper)
--------------------------------------------------------------------------------
See also:
III/205 : H-alpha Stars in Northern Milky Way (Kohoutek+ 1997)
Byte-by-byte Description of file: emitters.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 I2 h RAh Right ascension (J2000.0)
4- 5 I2 min RAm Right ascension (J2000.0)
7- 11 F5.2 s RAs Right ascension (J2000.0)
13 A1 --- DE- Declination sign (J2000.0)
14- 15 I2 deg DEd Declination (J2000.0)
17- 18 I2 arcmin DEm Declination (J2000.0)
20- 23 F4.1 arcsec DEs Declination (J2000.0)
25- 43 A19 --- IPHAS IPHAS source designation, JHHMMSS.ss+DDMMSS.s (1)
45- 50 F6.3 mag r'mag Sloan r' band magnitude
52- 56 F5.3 mag e_r'mag Sloan r' band magnitude error
58- 63 F6.3 mag r'-i' Sloan r'-i' colour index
65- 69 F5.3 mag e_r'-i' Sloan r'-i' colour index error
71- 76 F6.3 mag r'-Ha Sloan r'-Hα colour index
78- 82 F5.3 mag e_r'-Ha Sloan r'-Hα colour index error
84- 87 A4 --- Flag [cksmo ] Photometry/Cross-match flag (2)
--------------------------------------------------------------------------------
Note (1): Sexagesimal, equatorial position-based source name in the form:
JHHMMSS.ss+DDMMSS.s. The full naming convention for IPHAS sources has
the form "IPHAS JHHMMSS.ss+DDMMSS.s", where "J" indicates the position
is J2000. The "IPHAS" prefix is not listed explicitly in the
designation column.
Note (2): This column is used to flag any special circumstances related
to the photometry or if the object is in the vicinity of a Kohoutek
& Wehmeyer (1999, Cat. III/205) object.
Possible entries in this column are as follows:
c = the object does not have consistent magnitudes in any of the
IPHAS fields it has been observed in. This can be as a result
of source variability or poor photometric calibration due to
observations in less than ideal conditions.
m = the object is located in a IPHAS field where manual selection of
emitters took place.
o = the object is located in a IPHAS field where manual selection of
emitters took place and additionally the distribution of sources
in the r'-i' vs r'-Hα colour-colour plots in this field
looked unusual.
k = the object has been matched with a previously known Hα
emitter in the (Kohoutek & Wehmeyer, 1999, Cat. III/205)
catalogue using a matching radius of up to 30arcsec.
s = the object has been matched with a SIMBAD source.
--------------------------------------------------------------------------------
Acknowledgements:
Andrew Witham, arw_sent(at)yahoo.co.uk
(End) Andrew Witham [Southampton, UK], Patricia Vannier [CDS] 21-Dec-2007