Table Description:
A table of rotation measures derived from the content of lotsspol.spectra. This is supposed to be in line with RMTable version 1, https://github.com/CIRADA-Tools/RMTable.
This table is available for ADQL queries and through the TAP endpoint.
Resource Description:
The LOFAR Two Meter Sky Survey LoTSS DR2 (2022A&A...659A...1S) obtained radio data from 27% of the northern sky between 120 and 168 MHz in the year 2014 through 2020. This service publishes polarization spectra of extragalactic radio sources (radio galaxies and blazars) and the rotation measures derived from them. We also give redshifts for all sources. The data has a spatial resolution of 20 arcsec.
For a list of all services and tables belonging to this table's resource, see Information on resource ' Rotation Measures from the LOFAR Two Meter Sky Survey LoTSS DR2'
This table has an associated publication. If you use data from it, it may be appropriate to reference 2023arXiv230107697O (ADS BibTeX entry for the publication) either in addition to or instead of the service reference.
To cite the table as such, we suggest the following BibTeX entry:
@MISC{vo:lotsspol_rmtable, year=2022, title={ Rotation Measures from the {LOFAR} Two Meter Sky Survey {LoTSS} DR2}, author={O'Sullivan, S. and Shimwell, T. W. and Hardcastle, M. J. and Tasse, C. and Heald, G. and Carretti, E. and Brüggen, M. and Vacca, V. and Sobey, C. and C. L. Van Eck and Horellou, C. and Beck, R. and Bilicki, M. and Bourke, S. and Botteon, A. and Croston, J. H. and Drabent, A. and Duncan, K. and Heesen, V. and Ideguchi, S. and Kirwan, M. and Lawlor, L. and Mingo, B. and Nikiel, B. and Wroczyński, J. and Piotrowska, J. and Scaife, A. M. M. and van Weeren, R. J.}, url={https://dc.zah.uni-heidelberg.de/tableinfo/lotsspol.rmtable}, howpublished={{VO} resource provided by the {GAVO} Data Center} }
Sorted by DB column index. [Sort alphabetically]
Name | Table Head | Description | Unit | UCD |
---|---|---|---|---|
cat_id | Cat. # | Source ID in catalog | N/A | meta.id;meta.main |
ra | RA | Right Ascension [ICRS] of the polarised emission at epoch (this will often be an one extremity of the radio source). | deg | pos.eq.ra;meta.main |
dec | Dec | Declination [ICRS] of the polarised emission at epoch (this will often be an one extremity of the radio source). | deg | pos.eq.dec;meta.main |
datalink | Spectrum | Datalink for the spectrum | N/A | meta.ref.url |
rm | Rot. Meas. | Rotation measure | rad.m**-2 | phys.polarization.rotMeasure;meta.main |
rm_err | Err. RM | Total error in RM | rad.m**-2 | stat.error;phys.polarization.rotMeasure |
rm_err_snr | Rm_err_snr | Error in RM from signal to noise ratio only | rad.m**-2 | stat.error;phys.polarization.rotMeasure |
polint | Pol. intens. | Polarized intensity | Jy | phot.flux.density;phys.polarization.linear |
polint_err | Err. Pol.Int. | Error in Polarised Intensity | Jy | stat.error;phot.flux.density;phys.polarization.linear |
fracpol | Fracpol | Fractional (linear) polarization | N/A | phys.polarization.linear |
fracpol_err | Fracpol_err | Error in fractional polarization | N/A | stat.error;phys.polarization.linear |
rmsf_fwhm | Rmsf_fwhm | Full-width at half maximum of the RMSF | rad.m**-2 | instr.rmsf;stat.fwhm |
reffreq_pol | Reffreq_pol | Reference frequency for polarization | Hz | em.freq;phys.polarization |
l | L | Galactic Longitude | deg | pos.galactic.lon |
b | B | Galactic Latitude | deg | pos.galactic.lat |
pos_err | Pos_err | Position uncertainty | deg | stat.error;pos |
beamdist | Beamdist | Distance from beam centre (taken as centre of tile) | deg | pos.angDistance;instr.beam |
catname | Catname | Name of catalog this was taken from. | N/A | meta.note |
complex_flag | Complex_flag | Faraday complexity flag | N/A | meta.code |
complex_test | Complex_test | Faraday complexity metric | N/A | meta.note |
rm_method | Rm_method | RM determination method | N/A | meta.note |
ionosphere | Ionosphere | Ionospheric correction method | N/A | meta.note |
pol_bias | Pol_bias | Polarization bias correction method | N/A | meta.note |
flux_type | Flux_type | Stokes extraction method | N/A | meta.note |
beam_maj | Beam_maj | Beam major axis | deg | pos.angResolution;instr.beam;phys.angSize.smajAxis |
beam_min | Beam_min | Beam minor axis | deg | pos.angResolution;instr.beam;phys.angSize.sminAxis |
beam_pa | Beam_pa | Beam position angle | deg | pos.angResolution;instr.beam;pos.posAng |
reffreq_beam | Reffreq_beam | Reference frequency for beam | Hz | em.freq;instr.beam |
minfreq | Minfreq | Lowest frequency | Hz | em.freq;stat.min |
maxfreq | Maxfreq | Highest frequency | Hz | em.freq;stat.max |
channelwidth | Channelwidth | Typical channel width | Hz | em.freq;instr.bandwidth |
noise_chan | Noise_chan | Typical per-channel noise in Q;U | Jy | stat.error;instr.det.noise |
telescope | Telescope | Name of Telescope(s) | N/A | instr.tel |
int_time | Int_time | Integration time | s | time.duration;obs.exposure |
epoch_mjd | Epoch_mjd | Median epoch of observation | d | time.epoch |
obs_interval | Obs_interval | Interval of observation | d | time.interval |
leakage | Leakage | Instrumental leakage estimate | N/A | phys.polarization.linear |
dataref | Dataref | Data references | N/A | meta.bib.bibcode |
notes | Notes | Notes | N/A | meta.note |
reffreq_i | Reffreq_i | Reference frequency for Stokes I | Hz | em.freq;phys.polarization.stokes.I |
field | LoTSS pointing | LoTSS observation pointing name | N/A | meta.id;obs.field |
x | X | x-pixel coordinate within an individual LoTSS field, ranging from 0 to 3200, for a pixel width of 4.5 arcsec | pixel | pos.cartesian.x;instr.det |
y | Y | y-pixel coordinate within an individual LoTSS field, ranging from 0 to 3200, for a pixel height of 4.5 arcsec | pixel | pos.cartesian.y;instr.det |
snr_rmtools_mad | Snr_rmtools_mad | Signal to noise ratio based the peak polarized intensity divided by the estimated noise in the Faraday depth spectrum (where the noise is computed using the median deviation from the median of the polarized intensity, and then correcting to be equivalent to a Gaussian sigma). | N/A | stat.snr;phot.flux;phys.polarization |
ra_nvss | Ra_nvss | RA of the object in NVSS | deg | pos.eq.ra |
dec_nvss | Dec_nvss | Dec of the object in NVSS | deg | pos.eq.dec |
nvss_rm | Nvss_rm | Rotation measure of the object in NVSS | rad.m**-2 | phys.polarization.rotMeasure |
nvss_rm_err | Nvss_rm_err | Error in rotation measure of the object in NVSS | rad.m**-2 | stat.error;phys.polarization.rotMeasure |
i_nvss | I_nvss | Integrated Stokes I flux density from NVSS | mJy | phot.flux;phys.polarization.stokes.I |
p_nvss | P_nvss | Average peak polarized intensity from NVSS | mJy | phot.flux;phys.polarization.stokes.I |
pi_nvss | Pi_nvss | Percent polarization from NVSS | N/A | phys.polarization;arith.ratio |
separation_nvss | Separation_nvss | Difference between NVSS position and LoTSS DR2 position | arcsec | pos.angDistance |
lgz_size | Lgz_size | Largest angular size of the source | arcsec | phys.angsize;stat.max |
zphot | Zphot | Photometric redshift derived here from archive photometry (WISE, PanSTARRS, etc; cf. 2021A&A...648A...4D). | N/A | src.redshift.phot |
zphot_err | Zphot_err | Error in zphot | N/A | stat.error;src.redshift.phot |
phot_spec_z_best | Phot_spec_z_best | Nature of z_best: 0: phot, 1: spec | N/A | meta.code;src.redshift |
lgz_ra_deg | Lgz_ra_deg | RA of the host galaxy, mainly from NED. | deg | pos.eq.ra |
lgz_dec_deg | Lgz_dec_deg | Dec of the host galaxy, mainly from NED. | deg | pos.eq.dec |
z_best | Z_best | Best redshift available from the literature, typically from NED. | N/A | src.redshift |
num_in_field | Num_in_field | Number of polarized sources in the originating pointing. | N/A | meta.number;src |
medrm | Medrm | Median RM in the originating pointing. | rad.m**-2 | phys.polarization.rotMeasure;stat.median |
madrm | Madrm | Median absolute deviation of RM in the originating pointing. | rad.m**-2 | stat.mad;phys.polarization.rotMeasure |
medfpol | Medfpol | Median degree of polarization in the originating pointing (percent). | N/A | phys.polarization;stat.median |
madfpol | Madfpol | Median absolute deviation of degree of polarization in the originating pointing (percent). | N/A | stat.mad;phys.polarization |
ra_centre | Ra_centre | RA of field centre | deg | pos.eq.ra;obs.field |
dec_centre | Dec_centre | Dec of field centre | deg | pos.eq.dec;obs.field |
nchan | Nchan | Number of channels used in RM derivation | N/A | meta.number;em.bin |
source_name_dr2 | ILT name | Official source name assigned by the International LOFAR Telescope ILT. | N/A | meta.id |
ra_dr2 | Ra_dr2 | LoTSS DR2 RA of the centroid of the total radio intensity using pyBDSF. | deg | pos.eq.ra |
dec_dr2 | Dec_dr2 | LoTSS DR2 Dec of the centroid of the total radio intensity using pyBDSF. | deg | pos.eq.dec |
e_ra_dr2 | E_ra_dr2 | Error in ra_dr2 | deg | stat.error;pos.eq.ra |
e_dec_dr2 | E_dec_dr2 | Error in dec_dr2 | deg | stat.error;pos.eq.dec |
total_flux_dr2 | Total_flux_dr2 | Total radio flux at 144 MHz from pyBDSF. | Jy | phot.flux;em.radio |
e_total_flux_dr2 | E_total_flux_dr2 | Error in total_flux_dr2 | Jy | stat.error;phot.flux;em.radio |
maj_dr2 | Maj_dr2 | Semimajor axis of the radio emission | arcsec | phys.angSize.smajAxis |
min_dr2 | Min_dr2 | Semiminor axis of the radio emission | arcsec | phys.angSize.sminAxis |
pa_dr2 | Pa_dr2 | Position angle of the radio emission, north over west | deg | pos.posAng |
l144 | L144 | Spectral luminosity at 144 MHz in the rest frame of the source | W.Hz**-1 | phys.luminosity |
linearsize_kpc | Linearsize_kpc | Projected largest linear size | kpc | phys.size |
rrm | Rrm | The residual RM after subtraction of the average Galactic RM within an aperture of radius 1 degree (see the grm column). [Note galm] | rad.m**-2 | phys.polarization.rotMeasure;src.net |
grm | Grm | Average Galactic RM within an aperture of radius 1 degree from the Garching Faraday rotation sky v2. [Note galm] | rad.m**-2 | phys.polarization.rotMeasure |
grmerr | Grmerr | Error in grm. [Note galm] | rad.m**-2 | stat.error;phys.polarization.rotMeasure |
bzcat_name | Bzcat_name | Blazar source name in the ROMA-BZCAT catalogue (2015Ap&SS.357...75M) | N/A | meta.id.cross |
Columns that are parts of indices are marked like this.
The following services may use the data contained in this table:
VO nerds may sometimes need VOResource XML for this table.
This is using Version 2 of the Galactic Faraday rotation sky at https://wwwmpa.mpa-garching.mpg.de/ ̃ensslin/research/data/faraday2020.html.