J/MNRAS/436/718 Extremely faint planetary nebulae in SDSS (Yuan+, 2013)
Hunting for extremely faint planetary nebulae in the SDSS spectroscopic
database.
Yuan H.B., Liu X.W.
<Mon. Not. R. Astron. Soc., 436, 718-739 (2013)>
=2013MNRAS.436..718Y 2013MNRAS.436..718Y
ADC_Keywords: Planetary nebulae ; Spectroscopy ; Redshifts
Keywords: techniques: spectroscopic - planetary nebulae: general
Abstract:
Using ∼1700000 target- and sky-fibre spectra from the Sloan Digital
Sky Survey (SDSS), we have carried out a systematic search for
Galactic planetary nebulae (PNe) via detections of the [OIII]
λλ4959, 5007 lines. Thanks to the excellent sensitivity
of the SDSS spectroscopic surveys, this is by far the deepest search
for PNe ever taken, reaching a surface brightness of the [OIII]
λ5007 line down to about 29.0mag/arcsec2. The search leads to
the recovery of 13 previously known PNe in the Northern and Southern
Galactic Caps. In total, 44 new PN candidates are identified,
including seven candidates of multiple detections and 37 candidates of
single detection. The seven candidates of multiple detections are all
extremely large (between 21 and 154arcmin) and faint, located mostly
in the low Galactic latitude region and with a kinematics similar to
disc stars. After checking their images in Hα and other bands,
three of them are probably HII regions, one is probably associated
with a new supernova remnant, another one is possibly a true PN and
the remaining two could be either PNe or supernova remnants. Based on
sky positions and kinematics, seven candidates of single detection
probably belong to the halo population. If confirmed, they will
increase the number of known PNe in the Galactic halo significantly.
All the newly identified PN candidates are very faint, with a surface
brightness of the [OIII] λ5007 line between
27.0-30.0mag/arcsec2, and very challenging to be discovered with
previously employed techniques (e.g. slitless spectroscopy,
narrow-band imaging), and thus may greatly increase the number of
`missing' faint PNe. Our results demonstrate the power of large-scale
fibre spectroscopy in hunting for ultrafaint PNe and other types of
emission line nebulae. Combining the large spectral data bases
provided by the SDSS and other on-going projects (e.g. the LAMOST
Galactic surveys), it is possible to build a statistically meaningful
sample of ultrafaint, large, evolved PNe, thus, improving the census
of Galactic PNe.
Description:
We used the SDSS DR7 (Abazajian et al., 2009ApJS..182..543A 2009ApJS..182..543A)
spectroscopic data base in this work. For each spectrum from the SDSS
DR7 spectroscopic data base, we have performed Gaussian fitting to the
[OIII]λλ4959, 5007 lines around their rest wavelengths.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1a.dat 55 21 List of Recovered PNe and HII regions and
PN candidates of multiple detections
table1.dat 108 160 List of SDSS targets whose spectra show detectable
[OIII]λλ4959, 5007 emission from
Galactic PNe, HII regions and PN candidates
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See also:
V/84 : Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Acker+, 1992)
V/127 : MASH Catalogues of Planetary Nebulae (Parker+ 2006-2008)
Byte-by-byte Description of file: table1a.dat
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Bytes Format Units Label Explanations
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1 A1 --- Cat [AB] Category (G1)
3- 18 A16 -- Name Name of PNe or HII region
21- 28 A8 --- OName Other name
31- 35 F5.1 arcsec RadA [2/970]? Angular size for "Recovered PNe and HII
regions" in arcsec (Category A)
36 A1 --- --- ["]
39- 40 A2 --- l_RadB [≥] Limit flag on RadB
41- 43 I3 arcmin RadB [21/154]? Angular size for "PN candidates of
multiple detections" in arcmin (Category B)
44 A1 --- --- [']
46- 51 F6.1 km/s RV [-141/41]? Radial velocity
52- 55 A4 --- --- [km/s]
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1 A1 --- Cat [ABC] Category of source (G1)
3- 18 A16 -- Name Name of PNe or HII region, as in table1a
22- 24 I3 --- Seq [1/160] Sequential number of SDSS target
25 A1 --- n_Seq [deg] Note on the source (2)
27- 31 I5 d MJD [51690/54632] SSDS spectrum ID: MJD
32 A1 --- --- [-]
33- 36 I04 --- Plate SSDS spectrum ID: Plate number
37 A1 --- --- [-]
38- 40 I03 --- Fiber SSDS spectrum ID: Fiber number
42- 44 A3 --- Type Initial type in SDSS (3)
46- 53 F8.5 --- z [-0.002/4.246]?=- Redshift
55- 63 F9.5 deg RAdeg Right ascension (J2000)
65- 73 F9.5 deg DEdeg Declination (J2000)
75- 83 F9.5 deg GLON Galactic longitude
85- 93 F9.5 deg GLAT Galactic latitude
95- 99 F5.2 mag/arcsec2 S5007 [18.1/30.1] Line [OIII]λ5007 surface
brightness (4)
100 A1 --- n_S5007 [f] S5007 from [OIII]λ4959 line (5)
102-107 F6.1 km/s RV [-185/148] Radial velocity
108 A1 --- n_RV [f] RV from [OIII]λ4959 line (5)
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Note (2): Notes as follows:
d = Indicating haloes of PNe.
e = Indicating halo PNe and PN candidates.
g = PHL 932 is categorized in the SECGPN catalogue, but in fact an HII
region (Frew et al., 2010PASA...27..129F 2010PASA...27..129F).
Note (3): Initial types as follows:
GAL = galaxy
MD = M-dwarf
FTO = F-turnoff star
QSO = quasar
WD = white dwarf
HOT = hot star
ROS = ROSAT source
GD = G-dwarf
BHB = blue horizontal branch star
KG = K-giant
SER = hand-selected target
Note (4): Using the definition by Jacoby (1989ApJ...339...39J 1989ApJ...339...39J):
m5007=-2.5log(F5007)-13.74. S5007=m5007+2.5log(π*r2),
r=1.5-arcsec is the SDSS fibre radius.
Note (5): f: Based on [OIII]λ4959 line. The [OIII]λ5007 line of
this target is partly clipped as cosmic rays.
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Global Notes:
Note (G1): Category as follows:
A = Recovered PNe and HII regions
B = PN candidates of multiple detections
C = PN candidates of single detection
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Jul-2015