J/A+A/613/A58 Polarized point sources in LOTSS-HETDEX (Van Eck+, 2018)
Polarized point sources in the LOFAR Two-meter Sky Survey:
A preliminary catalog.
Van Eck C.L., Haverkorn M., Alves M.I.R., Beck R., Best P., Carretti E.,
Chyzy K.T., Farnes J.S., Ferriere K., Hardcastle M.J., Heald G.,
Horellou C., Iacobelli M., Jelic V., Mulcahy D.D., O'Sullivan S.P.,
Polderman I.M., Reich W., Riseley C.J., Rottgering H.,
Schnitzeler D.H.F.M., Shimwell T.W., Vacca V., Vink J., White G.J.
<Astron. Astrophys. 613, A58 (2018)>
=2018A&A...613A..58V 2018A&A...613A..58V (SIMBAD/NED BibCode)
ADC_Keywords: Polarization ; Radio sources
Keywords: Polarization ; Radio sources ; ISM: magnetic fields
Abstract:
We have produced a catalog of 92 polarized radio sources at 150MHz at
4.3-arcmin resolution and 1mJy rms sensitivity, which is the largest
catalog of polarized sources at such low frequencies. The data used
was from the LOFAR Two-Meter Sky Survey (LOTSS) initial release
(Shimwell et al., 2017, Cat. J/A+A/598/A104), (10h45m-15h30m right
ascension, 45-57° declination, 570 square degrees).
Description:
Visibility data taken from LOTSS, imaged in polarization, and had RM
synthesis applied. Resulting RM spectra were searched for polarization
peaks. Detected peaks that were determined to not be foreground or
instrumental effects were collected in this catalog. Source locations
(for peak searches) were selected from TGSS-ADR1 (J/A+A/598/A78).
Due to overlap between fields, some sources were detected multiple
times, as recorded in the Ndet column.
Polarized sources were cross-matched with the high-resolution LOTSS
images (Shimwell+, in prep), and WISE and PanSTARRS images, which were
used to determine the source classification and morphology.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
lotss-rm.dat 179 92 Catalog of polarized point sources
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See also:
J/ApJ/702/1230 : Rotation measure image of the sky (Taylor+, 2009)
J/A+A/598/A78 : The GMRT 150MHz all-sky radio survey (Intema+, 2017)
J/A+A/598/A104 : LOFAR Two-metre Sky Survey (Shimwell+, 2017)
Byte-by-byte Description of file: lotss-rm.dat
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Bytes Format Units Label Explanations
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2- 3 I2 --- CatID Catalog identification number
(sole pulsar, J1115+5030, is #99) (1)
6- 21 A16 --- TGSS ID Source name in TGSS-ADR1 catalog
(Intema et al., 2007, J/A+A/598/A78)
(JHHMMSS.s+DDMMSS)
23- 24 I2 h RAh Right Ascension (J2000)
26- 27 I2 min RAm Right Ascension (J2000)
29- 32 F4.1 s RAs Right Ascension (J2000)
34- 36 F3.1 s e_RAs Error in right ascension
38 A1 --- DE- Declination sign (J2000)
39- 40 I2 deg DEd Declination (J2000)
42- 43 I2 arcmin DEm Declination (J2000)
45- 48 F4.1 arcsec DEs Declination (J2000)
50- 53 F4.1 arcsec e_DEs Error in declination
55 I1 --- Ndet Number of independent detections
57- 61 F5.2 mJy PolInt Peak polarized intensity (in mJy/PSF unit)
63- 66 F4.2 mJy e_PolInt Error in peak polarized intensity
(in mJy/PSF unit)
69- 73 F5.2 rad/m2 Phi Faraday depth of peak polarized intensity
75- 78 F4.2 rad/m2 e_Phi Error in Faraday depth
80- 84 F5.2 % m Polarization fraction (of Stokes I)
86- 89 F4.2 % e_m Error in polarization fraction
91- 95 F5.1 rad/m2 NVSS-RM ?=0 Rotation measure from Taylor et al.
(2009, J/ApJ/702/1230) (2)
97-100 F4.1 rad/m2 e_NVSS-RM ?=0 Error in Taylor et al. (2009,
J/ApJ/702/1230) rotation measure (2)
102-106 F5.2 % NVSS-m ?=0 Polarization fraction from
Taylor et al. (2009, J/ApJ/702/1230) (2)
108-111 F4.2 % e_NVSS-m ?=0 Error in Taylor et al. (2009,
J/ApJ/702/1230) polarization fraction (2)
113-136 A24 --- Type Source Stokes I morphology
138 A1 --- LOFAR? [Y/N] Counterpart in high-resolution LOTSS?
142-143 A2 --- Optical? [YN? ] Optical counterpart identified?
146-179 A34 --- Comments Comments on morphology, optical ID
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Note (1): Single polarized pulsar is given CatID #99 to distinguish from
rest of catalog.
Note (2): Sources without counterparts in Taylor et al. (2009, Cat.
J/ApJ/702/1230) catalog have zero values for corresponding columns.
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Acknowledgements:
Cameron Van Eck, cameronve(at)gmail.com
(End) Patricia Vannier [CDS] 12-Jun-2018