Twenty years monitoring of extragalactic sources at 22, 37 and 87 GHz,,

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1 A&A 7, () DOI:./-:9 c ESO Astronomy & Astrophysics Twenty years monitoring of extragalactic sources at, 7 and 7 GHz,, H. Teräsranta,J.Achren, M. Hanski, J. Heikkilä, J. Holopainen,O.Joutsamo, M. Juhola, K. Karlamaa, S. Katajainen,P.Keinänen, P. Koivisto, M. Koskimies, P. Könönen,M.Lainela, A. Lähtenmäki, K. Mäkinen,T.Niemelä,P.Nurmi,T.Pursimo,R.Rekola,T.Savolainen, M. Tornikoski, J. Torppa, T. Valtonen,N.Varjonen,E.Vilenius, J. Virtanen, and S. iren Metsähovi radio observatory, Helsinki University of Technology, Metsähovintie, Kylmälä, Finland Tuorla Observatory, University of Turku, Piikkiö, Finland Received May / Accepted 7 June Abstract. Long term monitoring results from mid 99 to the end of of quasar observations at, 7 and 7 GHz done at the Metsähovi radio observatory are presented. Approximately 7 observations are published here. Key words. galaxies: active radio continuum: galaxies quasars: general astronomical data bases: miscellaneous. Introduction To better understand the behaviour of quasars, it is important to monitor them over a large range of frequencies. The sources selected in this study are radio loud, have a flat radio spectrum and have shown blazar flaring type behaviour at least in some frequency band. Due to the small size of our antenna (.7 m), the sample is limited to stronger sources with flux density S >. Jy. The Northen location of the antenna (latitude = N) limits the observed sources to those with declination higher than degrees, with some exeptions. The variability time scale of these sources at and 7 GHz is typically from months to years. Monthly monitoring would in most cases be enough in to produce representative flux curve. The sensitivity of the antenna, receivers and time given for the observations limit the yearly observations to under, which would allow a sample of sources to be observed monthly. Currently in the list there are over sources, partly as a result of selecting new flat spectrum sources for monitoring prior to the next gamma-ray observatories AGILE and GLAST. The stronger sources, which are also used for pointing the antenna, are observed daily, while for the new candidate sources must be limited to yearly to demonstrate their spectra and duty cycle. Table is also available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (.79..) or via Table is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (.79..) or via The complete Fig. is only available in electronic form at Observing system The Metsähovi radio telescope is a.7 m diameter radome inclosed antenna. The surface accuracy of the antenna,. mm rms, allows observations at over GHz, but the sea level location is not suitable for submillimeter observations, at least during the warm season. The receivers at and 7 GHz have HEMPT front ends operating at room temperature. The total noise temperatures are in the range of K DSB, depending on the season. The sigma rms values for a min integration, with good observing conditions are about.. Jy. Both receivers operate with dual beam mode. The Metsähovi antenna was upgraded by changing the antenna panels and back structure in 99. The effects of the better panels on the data reduction were described in Teräsranta et al. (99).. Final remarks The number of observations for each source is shown in Table. The data before mid 99 were published in Salonen et al. (97), Teräsranta et al. (97), Teräsranta et al. (99) and Teräsranta et al. (99). The weekly mean fluxes of the best sampled sources since the start of monitoring are shown in Fig. at and 7 GHz. The numerical data of flux densities from mid 99 to the end of is published in Table only at the CDS via anonymous ftp. The data format in Table is the following: object designation, other name, observing frequency (GHz), observation date, time in UT hours, time in minutes, flux density (Jy), sigma error estimate (Jy). The earlier High electron mobility pseudomorphic transistor. Double side band. Article published by EDP Sciences and available at or

2 77 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz Table. Number of observations at each frequency. Source n n7 n7 Total - 7 III Z OC DA AO C NRAO NRAO C OA C DA OH PKS OI Table. continued. Source n n7 n7 Total - OJ C C OL Mark C ON C 7 9 C OQ 7 9 OR C C. 7 9 OS C

3 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz 77 Table. continued. Metsahovi GHz III Z Source n n7 n7 total +7 C C O CYG X OX 7 OX BL Lac C - 7- CTA C data has been anylysed as in in Valtaoja et al. (9), Valtaoja et al. (99) and numerous other publications. Metsahovi 7 GHz Fig.. eekly mean flux density of observed sources at and 7 GHz. Acknowledgements. Part of this work was supported by the Academy of Finland and the ihuri foundation. References Salonen, E., Teräsranta, H., Urpo, S., et al. 97, A&AS, 7, 9 Teräsranta, H., Valtaoja, E., Haarala, S., et al. 97, A&AS, 7, Teräsranta, H., Tornikoski, M., Valtaoja, E., et al. 99, A&AS, 9, Teräsranta, H., Tornikoski, M., Mujunen, A., et al. 99, A&AS,, Valtaoja, E., Haarala, S., Lehto, H., et al. 9, A&A,, Valtaoja, E., Teräsranta, H., Urpo, S., et al. 99, A&A,, 7

4 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p Online Material

5 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p OC DA Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

6 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p +9 AO + Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued. Fig.. continued Metsahovi GHz Metsahovi 7 GHz Fig.. continued Fig.. continued. Metsahovi GHz Metsahovi 7 GHz C

7 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p NRAO OA 9 Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued Metsahovi GHz NRAO Metsahovi GHz + Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

8 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p C DA 9 Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued Metsahovi GHz + Metsahovi GHz OH 7 Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

9 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p PKS 7+7 OI 9. Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued Metsahovi GHz 7+7 Metsahovi GHz +99 Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

10 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p 7 + C 9. Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued OJ 7 9+ Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

11 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p OL 9 C 9. Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued Mark ON Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

12 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p 9 + C 79 Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued C 7 + Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

13 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p + OR Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued OQ -9 Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

14 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p C. OS Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued C. Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

15 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p C 79+ Metsahovi GHz Metsahovi GHz 9 Metsahovi 7 GHz Metsahovi 7 GHz 9 Fig.. continued Fig.. continued Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

16 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

17 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p OX 7 BL Lac Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued

18 H. Teräsranta et al.: Twenty years monitoring of extragalactic sources at, 7 and 7 GHz, Online Material p C C. Metsahovi GHz Metsahovi GHz Metsahovi 7 GHz Metsahovi 7 GHz Fig.. continued Fig.. continued CTA Metsahovi GHz 7 7 Metsahovi 7 GHz Fig.. continued