OVRO 40m Telescope

Data policy

The OVRO 40 m Telescope is providing a service to the astronomical community: Since 2008 over 1,500 blazars have been monitored on a ~3-day cadence at 15 GHz. Since January 2021 over 5,500 blazars have been monitored on an 11-day cadence. Caltech thanks the hundreds of astronomers worldwide who have contacted us, in accordance with our data usage policy, leading to an average of over one paper per month in refereed journals using 40 m Telescope data since 2008.

Unfortunately, we have learned recently of several violations of our Data Usage Policy in which people have downloaded data for a single source without informing us, downloaded data on multiple objects without prior permission, and/or neglected to include acknowledgments to our sponsors (see below).

If you have used OVRO 40 m Telescope data for any purpose, including both studies of radio lightcurves and publication of results derived from the lightcurves, without prior permission, please contact Sebastian Kiehlmann as soon as possible to discuss how to comply with our Data Usage Policy.

Acknowledgment to be included in all publications using 40m Telescope data:

"This research has made use of data from the OVRO 40-m monitoring program (Richards, J. L. et al. 2011, ApJS, 194, 29), supported by private funding from the California Insitute of Technology and the Max Planck Institute for Radio Astronomy, and by NASA grants NNX08AW31G, NNX11A043G, and NNX14AQ89G and NSF grants AST-0808050 and AST- 1109911."

If you have any questions about the intellectual property policies of California Institute of Technology, please contact our Office of the General Counsel.

Data examples

The following images demonstrate the quality of the OVRO 40m 15 GHz light curves.


OVRO 40m 15GHz light curves of the calibrators from 2008 to 2020.

3C286 and DR21 are the usual flux density calibrators. The absolute calibration error is about 5% of the total flux density. The observations and data reduction are described in Richards et al. 2011, ApJS, 194, 29. The following figure and the data shown therein are not allowed to be used in publications without explicit permission given by the OVRO 40m team.

Recently published light curves

OVRO 40m 15GHz light curves of PKS1502+106 from 2008 to 2020.

OVRO 15 GHz light curve of PKS1502+106 (black dots) as shown in Figure A.2 in Hovatta et al. 2020, accepted in A&A. The blue solid line highlights a Neutrino event originating from a sky region that includes PKS1502+106, which is showing strong flaring activity at 15 GHz during this period.

OVRO 40m 15GHz light curves of PKS1413+135 from 2008 to 2020.

OVRO 15 GHz light curve of PKS1413+135 (black dots) as shown in Figure 11 in Readhead et al. 2020, accepted in ApJ.