J/MNRAS/506/3540 ASKAP-EMU ESP LMC Radio Continuum Survey (Pennock+, 2021)
The ASKAP-EMU Early Science Project:
888 MHz Radio Continuum Survey of the Large Magellanic Cloud.
Pennock C.M., van Loon J.T., Filipovic M.D., Andernach H., Haberl F.,
Kothes R., Lenc E., Rudnick L., White S.V., Agliozzo C., Anton S.,
Bojicic I., Bomans D.J., Collier J.D., Crawford E.J., Hopkins A.M.,
Jeganathan K., Kavanagh P.J., Koribalski B.S., Leahy D., Maggi P.,
Maitra C., Marvil J., Michalowski M.J., Norris R.P., Oliveira J.M.,
Payne J.L., Sano H., Sasaki M., Staveley-Smith L., Vardoulaki E.
<Mon. Not. R. Astron. Soc. 506, 3540 (2021)>
=2021MNRAS.506.3540P 2021MNRAS.506.3540P (SIMBAD/NED BibCode)
ADC_Keywords: Magellanic Clouds ; Radio continuum ; Surveys ;
Planetary nebulae ; Active gal. nuclei
Keywords: surveys - planetary nebulae: general - Magellanic Clouds -
radio continuum: galaxies - radio continuum: ISM -
radio continuum: stars
Abstract:
We present an analysis of a new 120 deg2 radio continuum image of
the Large Magellanic Cloud (LMC) at 888MHz with a bandwidth of 288MHz
and beam size of 13.9"x12.1", from the Australian Square Kilometre
Array Pathfinder (ASKAP) processed as part of the Evolutionary Map of
the Universe (EMU) survey. The median Root Mean Squared noise is
58uJy/beam. We present a catalogue of 54612 sources, divided over a
Gold list (30866 sources) complete down to 0.5mJy uniformly across the
field, a Silver list (22080 sources) reaching down to <0.2mJy and a
Bronze list (1666 sources) of visually inspected sources in areas of
high noise and/or near bright complex emission. We discuss detections
of planetary nebulae and their radio luminosity function, young
stellar objects showing a correlation between radio luminosity and gas
temperature, novae and X-ray binaries in the LMC, and active stars in
the Galactic foreground that may become a significant population below
this flux level. We present examples of diffuse emission in the LMC
(HII regions, supernova remnants, bubbles) and distant galaxies
showcasing spectacular interaction between jets and intracluster
medium. Among 14333 infrared counterparts of the predominantly
background radio source population we find that star-forming galaxies
become more prominent below 3mJy compared to active galactic nuclei.We
combine the new 888MHz data with archival Australia Telescope Compact
Array data at 1.4GHz to determine spectral indices; the vast majority
display synchrotron emission but flatter spectra occur too. We argue
that the most extreme spectral index values are due to variability.
Description:
We present a catalogue of 54,612 radio sources detected with ASKAP at
888MHz. We also present a table of sources from this catalogue that
were classified as planetary nebula in Simbad and present our findings
on their true nature.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
catalog.dat 301 54612 ASKAP-EMU 888MHz catalogue of the LMC,
created using Aegean
table3.dat 177 114 ASKAP 888MHz radio detections within 10 arcsec
of sources at one time classed as potential PNe
list.dat 123 1 Information of fits image
fits/* . 1 ASKAP-EMU 888 MHz fits image of the LMC image
from which catalogue was created
--------------------------------------------------------------------------------
Byte-by-byte Description of file: catalog.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 6 A6 --- SourceList Source list (1)
8- 30 A23 --- EMU-ID EMU ID (G1)
32- 33 I2 h RAh Right ascension (J2000)
35- 36 I2 min RAm Right ascension (J2000)
38- 41 F4.1 s RAs Right ascension (J2000)
43 A1 --- DE- Declination sign (J2000)
44- 45 I2 deg DEd Declination (J2000)
47- 48 I2 arcmin DEm Declination (J2000)
50- 51 I2 arcsec DEs Declination (J2000)
53- 71 F19.15 deg RAdeg Right Ascension (J2000)
73- 98 E26.20 deg e_RAdeg Error in Right Ascension (J2000)
100-118 F19.15 deg DEdeg Declination (J2000)
120-145 E26.20 deg e_DEdeg Error in Declination (J2000)
147-153 F7.2 mJy/beam PeakFlux Peak flux density per beam at 888MHz
155-162 F8.2 mJy/beam e_PeakFlux ?=-1000 Peak flux density per beam error
164-170 F7.2 mJy IntFlux Integrated flux density at 888MHz,
calculated from a, b and peak flux and
the synthesised beam size
172-179 F8.2 mJy e_IntFlux ?=-1000 Integrated flux density error
181-186 F6.2 arcsec a Fitted semi-major axis
188-192 F5.2 arcsec e_a ?=-1 Fitted semi-major axis error
194-199 F6.2 arcsec b Fitted semi-minor axis
201-205 F5.2 arcsec e_b ?=-1 Fitted semi-minor axis error
207-212 F6.2 deg PA [] Fitted Position Angle
214-219 F6.2 deg e_PA ?=-1 Fitted Position Angle error
221-225 I5 --- Island Number of the island from which the
source was fit
227-228 I2 --- Source Number of source within the Island
230-250 F21.18 mJy/beam Background Flux density per beam measured from the
background map at the source position
252-271 F20.18 mJy/beam LocalRMS Flux density per beam measured from the
rms map at the source position
273-278 F6.3 mJy ResMean Mean of the residual flux remaining in the
island after fitted Gaussian is subtracted
280-299 F20.18 mJy Resstd Standard deviation of the residual flux
remaining in the island after fitted
Gaussian is subtracted
301 A1 --- Flags [024] Flags (2)
--------------------------------------------------------------------------------
Note (1): Source list as follows:
GOLD = sources with IntFlux>0.5mJy
SILVER = IntFlux<0.5mJy
BRONZE = less certain sources
Note (2): Flags as follows:
0 = good fit
2 = an error occurred during the fitting process (e.g., the fit did not
converge)
4 = component was forced to have the shape of the local PSF.
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Designation in Simbad
17- 18 I2 h RAh Right ascension (J2000)
20- 21 I2 min RAm Right ascension (J2000)
23- 26 F4.1 s RAs Right ascension (J2000)
28 A1 --- DE- Declination sign (J2000)
29- 30 I2 deg DEd Declination (J2000)
32- 33 I2 arcmin DEm Declination (J2000)
35- 36 I2 arcsec DEs Declination (J2000)
38- 60 A23 --- EMU-ID EMU ID (G1)
62- 66 F5.2 mJy/beam PeakFlux Peak flux density per beam at 888MHz
68- 71 F4.2 mJy/beam e_PeakFlux Peak flux density per beam error
73- 77 F5.2 mJy IntFlux Integrated flux density at 888MHz,
calculated from a, b and peak flux and the
synthesised beam size
79- 82 F4.2 mJy e_IntFlux Integrated flux density error
84- 86 F3.1 arcsec Delta Distance between the radio source and the
coordinates listed in Simbad
88- 91 A4 --- Class Classes of the sources, see Comments for
where there is doubt
93-177 A85 --- Comments Additional information which casts doubt
on the Class
--------------------------------------------------------------------------------
Byte-by-byte Description of file: list.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 24 I5 --- Nx Number of pixels along X-axis
26- 30 I5 --- Ny Number of pixels along Y-axis
32- 52 A21 "datime" Obs.date Observation date
54- 60 F7.3 MHz Freq Observed frequency
62- 68 I7 Kibyte size Size of FITS file
70- 83 A14 --- FileName Name of FITS file, in subdirectory fits
85-123 A39 --- Title Title of the FITS file
--------------------------------------------------------------------------------
Global notes:
Note (G1): "ES" or "EC", where "E" is early science data, "S" is an isolated
source and "C" is a component of a source.
--------------------------------------------------------------------------------
Acknowledgements:
Clara M. Pennock, c.m.pennock(at)keele.ac.uk
(End) Clara M. Pennock [Keele Univ., UK], Patricia Vannier [CDS] 06-Aug-2021