MOJAVE
(
Monitoring
Of
Jets
in
Active galactic nuclei with
VLBA
Experiments)
is a long-term
program to monitor radio brightness and polarization variations in jets
associated with active galaxies visible in the northern sky.
Approximately 2/3 of these were observed from 1994-2002 as part of
the
VLBA 2 cm Survey.
These jets are powered by the accretion of material onto
billion-solar-mass black holes located in the nuclei of active
galaxies. Their
rapid brightness variations and
apparent
superluminal motions indicate
that they contain highly energetic plasma moving nearly directly at us
at speeds approaching that of light. Our observations
are made with the world's highest resolution telescope: the
Very Long
Baseline
Array (VLBA) at a wavelength of 2 cm, which enables us to make full
polarization images with an angular resolution
better than 1
milliarcsecond (the apparent separation of your car's headlights parked
on the Moon, as seen from Earth). We are using these data to better
understand the
complex evolution and magnetic field structures of these jets on
light-year
scales, close to where they originate in the active nucleus.
For astronomers:
All calibrated (u,v) visibility and FITS data for the MOJAVE and 2 cm
Survey programs are available via html links on the
source pages. If you are interested in
Stokes Q,U,V (linear and circular polarization) FITS images, please
contact us.
If you intend to use
these data in a publication, we ask that you include an
acknowledgment of the MOJAVE (Lister and Homan, 2005, AJ, 130, 1389)
and 2cm Survey (Kellermann et al., 2004, ApJ, 609, 539) programs, and
to please contact us
so we can add a link to our external
publications page.
WHAT'S NEW:
VLBA Archival Data at 2 cm:
In order to fill in temporal gaps in the coverage on selected jets, we
are currently adding 15 GHz data from the VLBA archive. These epochs
are listed on the individual source pages, and will be available for
public download after the publication of our main kinematics paper
(Lister et al., in preparation, slated for completion in Spring 2008).
MOJAVE in the GLAST
Era: Regular VLBA observations of the MOJAVE sample
have been approved by NRAO to continue through June 2009. These are
being
carried out at the approximate rate of 25 AGN per month at 2 cm
wavelength. Each AGN is observed every two to twenty-four months,
depending on its rate of angular evolution on the sky. The
current list of sources being monitored can be found in our
information table. After
the launch of GLAST in Spring 2008, up to 100 additional LAT-detected
gamma-ray AGN that have correlated 2 cm VLBA flux exceeding ~100 mJy
will be added to the sample. The current sample includes:
- all currently known EGRET gamma-ray AGN above
declination -20°
- 33 low-luminosity AGN (15 GHz luminosity < 1026
W/Hz)
- 8 gigahertz-peaked spectrum sources
- 11 AGN from the previous 2cm Survey that have
unusual kinematics.
Movies: On
our
movies page you can click
on the name of an active galaxy and get a MPEG movie showing its total
intensity and linearly polarized jet evolution over the last 4 years.
Clicking
on a thumbnail image will display a movie showing the total intensity
evolution in the jet over the last twelve years (or a shorter time
interval, depending on available data). Note that some movies contain
blank frames due to missing temporal coverage - if you have published 2
cm VLBA data on any AGN
listed on this web site and wish to contribute them to our online
archive,
please let us know!
Kinematics Plots: Plots
are now available for selected
jets in
the MOJAVE survey showing the separation of individual jet
features with respect to the (presumed stationary) core feature as a
function of time. These are subject to change as we add new epochs.
MOJAVE Phase-II:
During 2006 (BL137), a single multi-frequency VLBA epoch at
8.1, 8.4, 12.1
and 15.3 GHz was obtained for all sources in the MOJAVE sample. These
are currently being reduced, and are being used to explore the
properties
of
intervening gas responsible for modifying the observed polarization of
the jet emission.