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, as seen by
an astronaut on the Moon). 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, and how this
activity is correlated with gamma-ray emission detected by
NASA's Fermi
observatory.
For astronomers:
All calibrated (u,v) visibility and FITS data for the
MOJAVE and Boston U 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
please contact us so we can add a link to our
external publications page, and ask that you
include the following acknowledgment: "This
research has made use of data from the MOJAVE
database that is maintained by the MOJAVE
team (Lister
et al., 2018, ApJS, 232, 12)."
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WHAT'S
NEW:
MOJAVE program approved until August 2021: We have
received priority 'A' status on the VLBA starting in Aug.
2019 to conduct monthly simultaneous 15+22+43 GHz monthly
observations of 25
blazars, and observe 30 targets (drawn from a pool
of 63 AGNs) every two months at 15 GHz (2048 Mbps).
This represents the first large scale high resolution
multi-epoch study of Faraday rotation measure and spectral
gradients in AGN jets.
New Kinematics and Parent
Population Analysis Paper: We have analyzed the
pc-scale jet kinematics of 409 bright radio-loud AGNs
based on 15 GHz VLBA data obtained between 1994 August 31
and 2016 December 26. Our results combined with other
speeds from the literature indicate a strong correlation
between apparent jet speed and synchrotron peak frequency,
with the highest jet speeds being found only in low-peaked
AGNs. Using Monte Carlo simulations, we find best
fit parent population parameters for a complete sample of
174 quasars above 1.5 Jy at 15 GHz., and show that they
are consistent with powerful FR II class radio galaxies.
The manuscript was published
in ApJ in March 2019.
New MOJAVE Flux
Density-Limited Sample (1.5JyQC): Using data
from the VLBA, UMRAO, RATAN-600, and OVRO-40m telescopes,
we have constructed a new
complete '1.5 Jy Quarter Century' sample consisting
of all 232 non-lensed AGN north of declination -30 degrees
known to have exceeded 1.5 Jy in VLBA flux density at 15
GHz between 1994.0-2019.0.
Stacked Image Analysis
Paper: We have completed
a new analysis of the shapes and opening angles of
AGN jets in the MOJAVE survey, which shows that the
typical jet geometry is close to conical on scales from
hundreds to thousands of parsecs, while a number of
galaxies show quasi-parabolic streamlines on smaller
scales. A true jet geometry in a considerable fraction of
AGNs appears only after
stacking epochs over several years. Individual
stacked images can be found on the data
archive pages, and a complete set (956 Mb) is
available here.
Polarization Maps Paper: A new
paper appeared in ApJ Supplement series containing
5321 milliarcsecond-resolution total intensity and linear
polarization VLBA 15 GHz maps of 437 AGNs. The
majority of the AGNs were observed on 5 to 15 occasions
between 1996 January 19 to 2016 December 26, at
intervals ranging from a month to several years, with the
most typical sampling interval being six months. The full
set of images is available here.
VLBA L Band Data: In 2010, D. Gabuzda and
collaborators at Univ. College Cork observed the original
MOJAVE AGN sample at 4 frequencies in L Band with the VLBA
to investigate jet polarization and Faraday rotation
properties. We have added the preliminary u,v visibility
data and images from this
program to the individual MOJAVE source pages in our
data
archive.
MOJAVE is a VLBA Key
Science Project:
The MOJAVE program has been designated a Key
Science
Project by NRAO, in recognition of its contributions
and impact on the astrophysics community.
Blazar Monitoring Program
List:
Most of the blazars in MOJAVE are monitored at other
wavelengths by a variety of instruments. This blazar
monitoring
list page contains a sortable table of all blazars
known to be monitored at optical wavelengths, as well as
known TeV-emitting AGNs and MOJAVE-monitored sources.
Superluminal Motion
Demonstration Applets and Lab Activities:
The MOJAVE collaboration has developed several software
applets that demonstrate the principle of apparent
superluminal motion. One is a Flash
software
applet developed by REU student Quinn Looker and
Prof. Matthew Lister of Purdue University, and the other
is
a 3-D Vpython-based simulation recently developed by Prof.
Dan Homan of Denison University. The Vpython
applet and an accompanying laboratory exercise for
an introductory astronomy level course can be accessed at
http://personal.denison.edu/~homand/superluminal/
Joint Fermi-MOJAVE
papers: We have found several strong
connections between the VLBA radio jet properties of
MOJAVE blazars and their Fermi-detected gamma-ray
emission. Details have been published in Lister
et al. 2011, in Pushkarev,
Kovalev,
&
Lister 2010, Savolainen
et
al. 2010, Pushkarev
et
al. 2009, Lister
et
al. 2009, and Kovalev
et
al. 2009. In addition, we continute to contribute to
multiwavelength studies of individual AGN, e.g. 3C390.3: Arshakian
et
al. 2010, 1510-089: Abdo
et
al. 2010, 3C 454.3: Vercellone
et
al. 2010, 1502+106: Abdo
et al. 2009, J0948+0022: Abdo
et al. 2009, and NGC 1275: Abdo
et al. 2009. For a full list please visit our publications
page.
The
MOJAVE
program
is supported under NASA-Fermi grants NNX15AU76G
and NNX12A087G. Any
opinions, findings, and conclusions or recommendations
expressed on this website are those of the authors and
do not necessarily reflect the views of NASA. The
National Radio Astronomy Observatory is a facility of
the National Science Foundation operated under
cooperative agreement by Associated Universities,
Inc.
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