OVRO 40m Telescope

News

Nov 22, 2017
Database Updates

The OVRO 40-m data available here have now been updated until Nov 14, 2017. The current reduction version is HL26. Due to a change in the reduction pipeline some data points that were flagged in older data releases now appear in the light curves. This is not intended and will be fixed as soon as possible. This affects data before May 2014 in this and previous data relseases.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

Sep 28, 2017
Database Updates

With this data base update we fix an issue that has been introduced with the last data release of Sep 15, 2017. During the epoch 2017-01-27 (MJD 57780) to 2017-04-09 (MJD 57852) the absolute calibration was off scale. This is fixed now. The flagging issue mentioned previously still affects these data and will be fixed soon.

Sep 15, 2017
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until Sep 12, 2017. The current reduction version is HL26. Due to a change in the reduction pipeline some data points that were flagged in older data releases now appear in the light curves. This is not intended and will be fixed as soon as possible. This affects data before May 2014 in this and the previous data relsease.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

July 24, 2017
New website design

The OVRO 40-m website appears in a new, responsive design that adjusts with the display size and the users prefered font size.

May 21, 2017
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until April 9, 2017. The current reduction version is HL26. Between Jan 27 and Mar 11, 2017 the calibration sources showed a correlated, decreasing trend in the calibrated flux. This decrease was later found to be an effect of precipitation in one of the feeds. The combined data of the calibration sources during this period was fitted with a cubic spline. All data during this period is scaled by this spline to correct for the trend. Any variability analysis using data over that period should be done with extra care. During the period Mar 11 to Apr 5, 2017 receiver problems became obvious and the receiver was taken down on Apr 5, 2017. Precipitaion in the feed was found to be the origin of the problems. No data is published for the period Mar 11 to Apr 9, 2017. Observations continue since Apr 10, 2017.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

Dec 6, 2016
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until November 15, 2016. The current reduction version is HL26. Changes to the previous version (HL24) include a fix to a bug that resulted in a small number of outliers in the light curves. This affects all data since 2008. Between Aug 1 and Nov 24, 2015 the receiver was not working optimally, and the noise in the data is higher during this period. Any variability analysis using data over that period (especially in sources less than about 200 mJy in brightness) should be done with extra care.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

Feb 25, 2016
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until February 15, 2016. The current reduction version is HL24. The data since June 1, 2014 are taken with a new receiver and should be considered preliminary. Changes to the previous version (HL23) include a fix to a focus correction bug, affecting all data taken since June 1, 2014. In addition, the total flux density is now calculated as the weighted mean of the two circularly polarized flux densities, increasing the signal-to-noise compared to HL23. Between Aug 1 and Nov 24, 2015 the receiver was not working optimally, and the noise in the data is higher during this period. Any variability analysis using data over that period (especially in sources less than about 200 mJy in brightness) should be done with extra care.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

Dec 10, 2015
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until August 1, 2015. The current reduction version is HL23. The data since June 1, 2014 are taken with a new receiver and should be considered preliminary. At the moment, only single polarization of data is included and we expect the noise in the light curves to decrease when we add the second polarization.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

May 22, 2014
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until May 19, 2014. We are currently commissioning a new receiver on the 40-m telescope so that there will likely be a longer gap before the next reduction. The current reduction version is HL19.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

April 4, 2014
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until April 2, 2014. Note that data since December 12, 2013 are still preliminary and may change up to 5% during the future calibrations. The current reduction version is HL19.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

February 5, 2014
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until February 2, 2014. Note that data since December 12, 2013 are still preliminary and may change up to 5% during the future calibrations. The current reduction version is HL19.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

January 24, 2014
New OVRO publications!

Check out our recently accepted publications on the radio variability of blazars Connecting radio variability to the characteristics of gamma-ray blazars and our work analyzing optical, radio and gamma-ray data Connection between optical and gamma-ray variability in blazars.

December 16, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until December 12, 2013. The current reduction version is HL19.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

October 29, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until October 27, 2013. The current reduction version is HL19. Note that data since July 30, 2013 are still preliminary and may change up to 5% during the future calibrations.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

September 24, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until September 22, 2013. The current reduction version is HL19. Note that data since July 30, 2013 are still preliminary and may change up to 5% during the future calibrations.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

July 17, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until July 15, 2013. The current reduction version is HL19. Note that data since January 18, 2013 are still preliminary and may change up to 5% during the future calibrations.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

June 5, 2013
Mrk421 increasing its 15 GHz flux density

Following the extreme high-energy flaring in April, Mrk421 is increasing in flux density at 15 and 95 GHz. Check our ATel on this!

June 5, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until May 2, 2013. The current reduction version is HL19. Note that data since January 18, 2013 are still preliminary and may change up to 5% during the future calibrations.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

May 3, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until April 30, 2013. The current reduction version is HL19. Note that data since January 18, 2013 are still preliminary and may change up to 5% during the future calibrations.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

April 4, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until April 2, 2013. The current reduction version is HL19. Note that data since January 18, 2013 are still preliminary and may change up to 5% during the future calibrations.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

March 1, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until February 27, 2013. The current reduction version is HL19. Note that data since January 18, 2013 are still preliminary and may change up to 5% during the future calibrations.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

January 24, 2013
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until January 17, 2013. The current reduction version is HL19. The data since May 17, 2012 until January 4, 2013 were calibrated using DR21 (with a flux density set to 19.04 Jy based on our 4-year average) instead of our usual calibrator 3C 286 as the flux calibrator. This means that the data for all sources since May 17, 2012 have changed from the previous released versions.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

November 12, 2012
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until November 7, 2012.The current reduction version is HL19. Data from May 17 to November 7 are still preliminary and may change up to 5% during the future calibrations. Ifyou download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This way we can also inform you if these data change significantly in the future. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

October 2, 2012
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until September 30, 2012. The current reduction version is HL19. Data from May 17 to September 30 are still preliminary and may change up to 5% during the future calibrations.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

June 22, 2012
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until May 16, 2012. The current reduction version is HL18. The next data update is anticipated for the end of July 2012.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

April 27, 2012
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until April 24, 2012. The current reduction version is HL18.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

March 27, 2012
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until March 24, 2012. The current reduction version is HL18.

If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This is highly recommended for the new data so that we can inform you about the changes to the data, and also check the quality of the final light curve. If you have questions about specific sources, don't hesitate to contact us. A list of all AGN monitored at OVRO can be found here. If you wish to obtain data for a source not listed on our data page, please contact us via email.

February 28, 2012
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until February 25, 2012. The current reduction version is HL18. If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This way we can also inform you if these data change significantly in the future.

January 24, 2012
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until January 22, 2012. We fixed a minor bug in the data reduction pipeline which caused some unreliable flux measurements to slip through our automated flagging process. This will affect some individual flux measurements taken after August 12, 2010, mainly by removing outliers or high-rms observations from the light curves. The current reduction version is HL18. If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This way we can also inform you if these data change significantly in the future.

January 6, 2012
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated until December 17, 2011 and monthly updates are planned. The current reduction version is HL17. These data are still preliminary and may change slightly during the future calibrations. We note that some sources observed within 40 degrees of the Sun between August and October 2011 may have an additional 1-5% systematic error. If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. This way we can also inform you if these data change significantly in the future.

April 8, 2011
Database Updates

The OVRO 40-m data available here (user name guest, no password) have now been updated and monthly updates are planned. The data in 2008 and 2009 is identical to that to be published in Richards et al. (2011, ApJS, in press). Data since late 2010 have been collected with a new control system and reduced using a new pipeline. Although this is intended to be identical to the old, it is still preliminary and may change slightly in the near future. The current reduction version is HL15_MERGED.

Also, please note the new CSV format for our data. Timestamps are now provided as numeric modified Julian dates (MJD) instead of formatted strings and some unnecessary columns have been removed.

March 24, 2010
Detection of Radio Emission from V407 Cyg

The OVRO 40m team, along with our F-GAMMA collaborators, reported the first detection of radio emission from the symbiotic star V407 Cyg, which may be the counterpart of a recent Fermi-GST gamma-ray transient. Details are in ATel #2506.

December 9, 2009
Initial Public Release

We are happy to announce the initial public release of our blazar monitoring data. Data are now available from the "Data" tab above (or click here). When prompted, use user name guest and leave the password field empty.

The initial data release includes data for the 1158 CGRaBS we monitor, plus calibrators 3C 286, 3C 48, and DR 21, from 1 Jan 2008 through 16 Nov 2009. Incremental updates with more recent data will begin soon and continue regularly thereafter. This release does not include any "soft-flagged" data. Please be aware that some sources exhibit what we believe to be artifacts of pointing problems in early 2008 (e.g., J0217+0144). We are working to identify and eliminate affected data.

These data are being made available to the public as a service to the astronomical community. If you download and make use of these data, we request that you inform us via email with a brief description of your project or publication so that we may keep track of the impact of our work. Please remember that the collection and processing of these data represent a major effort. While we encourage open sharing and use of these data, publication or use without proper attribution AND a substantial additional scientific contribution to the work is inappropriate and is not permitted.

March 3, 2009
beta4 Re-release

The beta4 data have been re-uploaded after an error with the soft flagging was noticed. If you downloaded beta4 data prior to March 3, 2009, please take a moment to replace your files with our latest upload. We apologize for the inconvenience.

February 27, 2009
beta4 Data Release

We are pleased to present our latest data release: beta4! Of particular note is the introduction of soft flags. Measurements that are soft flagged are to be viewed with caution: although they are still useful, we think their error bars significantly underestimate the effects of systematics. Flagged measurements are plotted in grey. On the other hand, the error bars of unflagged measurements represent an accurate uncertainty.

February 14, 2009
Public Main Page and Cosmetic Upgrades

The main, news, and contact pages are now open to the public. The data remain password protected. The data return now displays the reduction version and our definition of variability index.

January 2, 2009
Updated with Database Access

The website has now been interfaced with our 40m database. User may now search for sources by name or position. Doing so will query the database for matches, and compile some basic statistics for the returned sources. The plots and files returned are still pre-generated, but we are now working towards weekly updates. Data back to June, 2007, is now provided for our pointing sources.

October 10, 2008
Release to Fermi Collaboration

The website was released to the Fermi collaboration. Current data release begins at July 1, 2008. Data gathered prior to this date requires further processing to correct for an inaccurate pointing model. Navigate to the Data page and choose your favourite source. Note that this does not yet interface with our database. Regrettably, until the database interface is up, our data will not be searchable. Keep track of the ongoing updates to this site by subscribing to our RSS feed.