J/A+AS/135/273 J/A+AS/135/273 408MHz obs. of GPS sources from JVAS survey A Marecki H Falcke J Niezgoda S T Garrington A R Patnaik Astron. Astrophys. Suppl. Ser. 135 273 1999 1999A&AS..135..273M Radio sources catalogs galaxies: active quasars: general radio continuum: general Observations with MERLIN at 408 MHz have been used to establish the low-frequency part of the spectra of more than a hundred compact radio sources taken from the part of the Jodrell Bank-VLA Astrometric Survey (JVAS) limited by 35{deg}<={delta}<=75{deg}. These sources were selected from JVAS and other catalogues to have convex spectra between 1.4 and 8.4GHz, characteristic of Gigahertz Peaked Spectrum sources. We have confirmed convex shapes of the spectra of 76 objects.

IAU IAU name --- RAh Right ascension (J2000) h RAm Right ascension (J2000) min RAs Right ascension (J2000) s DEd Declination (J2000) deg DEm Declination (J2000) arcmin DEs Declination (J2000) arcsec S408MHz Flux density at 408 MHz mJy Type Object type number=1 BL: BL Lac object BS: blue stellar object (without the spectrum - basically a quasar) BG: blue galaxy? CW: crowded field - too many objects for a clean identification EF: empty field G: galaxy NS: neutral stellar object (same magnitude in both E and O prints) OB: obscured field Q: quasar RS: red stellar object --- IAU IAU name --- RAh Right ascension (J2000) h RAm Right ascension (J2000) min RAs Right ascension (J2000) s DEd Declination (J2000) deg DEm Declination (J2000) arcmin DEs Declination (J2000) arcsec Type Object type number=1 BL: BL Lac object BS: blue stellar object (without the spectrum - basically a quasar) BG: blue galaxy? CW: crowded field - too many objects for a clean identification EF: empty field G: galaxy NS: neutral stellar object (same magnitude in both E and O prints) OB: obscured field Q: quasar RS: red stellar object --- Seq Sequence number on our list --- IAU IAU name --- S0 S_0_ parameter number=1 S_0_ and nu_0_ are just parameters in the formula (2): S({nu})=S_0_/(1-e^-1^)*({nu}/{nu}_0_)^k^*(1-e^-({nu}/{nu}_0_)^l-k^) mJy nu0 {nu}_0_ parameter number=1 S_0_ and nu_0_ are just parameters in the formula (2): S({nu})=S_0_/(1-e^-1^)*({nu}/{nu}_0_)^k^*(1-e^-({nu}/{nu}_0_)^l-k^) GHz k Spectral index of the rising part --- l Spectral index of the declining part --- Smax Flux density at the maximum mJy numax Frequency of the maximum flux density GHz Flag Note number=2 We fitted the so called broken power-law to our spectra - see formula (2) in the paper. Even though it seems to be the physically more sensible choice for a model spectrum compared to a simple second-order polynomial, it has the disadvantage that it is unconstrained if the peak of the spectrum falls beyond the 2nd highest or below the 2nd lowest available frequency. In these cases we fixed the peak of the model spectrum (i.e. Smax and numax) at the peak of the measured data - this was usually the measurement at 4.85GHz - and marked the fit as "unconstrained" by putting a "+" sign in col. 61. --- Patricia Bauer CDS 1999Mar02Andrzej Marecki <amr@astro.uni.torun.pl> J_A+AS_135_273.xml