The MOJAVE AGNProgramDept. of PhysicsPurdue University(currently on sabbatical at Univ. College Cork, Ireland)Matthew Lister

VLBA

Fermi

UMRAOOVRO

Chandra1MOJAVE CollaboratorsM. Lister (P.I.), N. Cooper, B. Hogan, S. Kuchibhotla, T. Hovatta (Purdue)T. Arshakian, C.S. Chang, L. Fuhrmann, Y. Kovalev, A. Lobanov, A. Pushkarev, T. Savolainen, J. A. Zensus (Max Planck Inst. for Radioastronomy, Germany)M. and H. Aller (Michigan)M. Cohen, A. Readhead (Caltech) D. Homan (Denison)M. Kadler, M. Boeck (U. Erlangen-Bamberg, Germany)K. Kellermann (NRAO)Y. Kovalev (ASC Lebedev, Russia)E. Ros (Valencia, Spain)N. Gehrels, J. McEnery, J. Tueller (NASAGSFC)

MonitoringOfJets inActive Galaxies withVLBAExperimentsVery Long Baseline Array

The MOJAVE Program is supported under NASA Fermi Grant NNX08AV67G and NSF grant 0807860-AST.FermiOutlineThe MOJAVE program: present and future

Kinematics of highly beamed AGN jetsparsec-scale radio imagingconnections with gamma-ray emission

Case study: Impact of 8 antenna VLBA array on jet studiesThe MOJAVE ProgramRegularly taking VLBA images of the ~300 brightest jets in the northern sky

Jet kinematics on decadal timescalesfull polarization images provide additional information on jet magnetic fields

Concurrent multiwavelength studies of the sample

Currently funded by the National Science Foundation and NASA

MonitoringOfJets inActive Galaxies withVLBAExperimentshttp://www.physics.purdue.edu/MOJAVELister et al., 2009, AJ, 137, 37184Scientific Highlights: Jet KinematicsMotions of superluminal bright features are related to true flow speedsome near-stationary features are seen (6%), more common in lower power BL Lac jets

Most AGN jets are only mildly relativistic ( ~ few)extended tail to speed distributionsome exceedingly rare jets (blazars) have ~ 50

Fastest jets all have very high synchrotron and gamma-ray luminosity (not likely a beaming effect)

Lister et al., 2009, AJ, 138, 1874 Lister et al., 2009, ApJ 696, L22Scientific Highlights: AccelerationsAccelerations of features are common (at least 50%) in both speed and direction sudden events: collimation of 3C279 jet continuous: curved motions around stationary bendsunpredictable: different accelerations/non-accelerations seen in the same jet

Positive (speeding up) accelerations more prevalent close to the base of the jet

jet flows are still becoming organized on parsec scales

Homan et al., 2003, ApJ, 589, L9Homan et al., 2009, ApJ, 706, 1253

Image from March 1996

Recent image: June 2009Jet Activity StatesAt any given time, only the energized portion of a broader jet is visible

Activity states of jets evolve over timelong quiescent periods of no jet ejections are seennew features ejected at new position angles (precession?)

Fermi is preferentially detecting currently active jets (brighter than their historical average radio level) (Kovalev et al. 2009, ApJL 696, L17)

Stacked image: 1995-2009Lister et al., 2009, AJ, 137, 37181308+3268What makes a jet gammaray bright?Light output peaked at high energy(more important at fainter gamma-ray levels)

Preferred viewing angle (aimed toward us)

Fast intrinsic jet speed (highly beamed)

High current activity state

Complex combination of:Blazar gamma-ray emission is directly related to pc-scale radio jet propertiesmore Doppler boosting in gamma-rays than radio (Lister et al. in prep)Gamma-ray emission may be intrinsically anisotropic (Savolainen et al. 2010)

PreliminaryOther MOJAVE StudiesIntraday variability (Kuchibhotla, Ph.D. Thesis 2010)rapid flux variations common in quasars, rare in BL Lacsorigin is likely galactic ISM scattering, but requires compact, highly beamed emitting regions

Chandra survey (Hogan et al. 2010, ApJ in press)X-ray jets are ubiquitous in blazars with extended radio emissionIC-CMB model requires relativisic jet speeds on kpc-scales

Deep VLA imaging survey (Cooper, Ph.D. Thesis 2010, Kharb et al. 2010, ApJ)low-energy peaked BL Lacs can have FR I or II jet morphologies

MOJAVE: Whats in storeKinematics of complete set of gamma-ray blazars

Circular and linear polarization jet evolution

SED and optical spectroscopy analysis

Extension of sample down to 1.5 Jy and dec > -30

Extended Chandra and EVLA surveys

Case Study: Science Impact of Dropping Two Inner VLBA AntennasImage qualitytotal intensity and linear polarization

Model fittingpositions and flux densities of Gaussian fits

What is the project about?Define the goal of this projectIs it similar to projects in the past or is it a new effort?Define the scope of this projectIs it an independent project or is it related to other projects?

* Note that this slide is not necessary for weekly status meetings

13Observational DatasetBL149CP: MOJAVE Program24 hour run on Sept 17, 201015 GHz, 512 Mbps, continuum, dual pol.30 compact AGN jets, 0.2 to 16 Jyscans interleaved to optimize u,v coverage~35 min total integration time per sourceexcellent weather at all 10 sites, minimal downtime

Data were reduced twice:1. with all antennas2. with two inner antennas (KP and LA) completely flagged

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Image comparison: compact jets8 antennas10 antennas

10 antennas10 antennas8 antennas8 antennasImage comparison: extended jets

8 antennas10 antennas8 antennas8 antennas10 antennas10 antennas

Image rms noise slightly higher than theoretical 2 antenna lossExtended jets suffer higher image rms loss than compact jets

Most of extended jet emission lostGaussian model fittingEvolutionary changes in jets are most simply tracked by modeling emission as discrete GaussiansPositional accuracy: typically ~1/5 beamwidth (0.2 mas)

Comparison: Gaussian component flux densitiesNegligible difference for strongest components (> 300 mJy)Strong difference between 8 and 10 ants. for weaker components

Comparison: Astrometry (cont)Typical offset from 10 antenna-fitted position is 0.1 masPositional error strongly dependent on flux density of feature

Nominal positional accuracyRecording sensitivity versus u,v coverageWhat would 2X improved VLBA sensitivity look like for AGN jets?Image using all 10 antennas, flagging 3/4 of all the IFs

(10 antennas of IFs)Full array, low recording bandwidthColorscale = fractional linear polarizationRecording sensitivity versus u,v coverageWhat would 2X improved VLBA sensitivity look like for AGN jets?Image using all 10 antennas, flagging no IFs

10 antennas all IFsFull array, high recording bandwidthColorscale = fractional linear polarizationRecording sensitivity versus u,v coverageWhat would 2X improved VLBA sensitivity look like for AGN jets?Image using all 8 antennas, flagging no IFs

(8 antennasall IFs)Reduced array, high recording bandwidthColorscale = fractional linear polarizationSummary: Loss of 2 inner VLBA antennas = 38% loss in available baselinesbut higher rise in image noise10 antenna VLBA is already a minimum array for imaging

Improving recording bandwidth cannot make up for loss of short interferometric baselinesemission on scales > 3 mas becomes invisible to the VLBA (at 15 GHz)flux and positional measurements significantly degraded for 45% of jet features in MOJAVE surveystrongly affects imaging science capabilities, and will affect astrometry of weaker, less compact features

MOJAVE is a comprehensive program aiming to understand the physics of highly relativistic jets from black holes- Lorentz factors up to at least 50- sudden/smooth, parallel and perpendicular accelerations

MOJAVE+Fermi combination is a providing a huge leap forward in our understanding of AGN outflows, emission and particle acceleration

MOJAVE project webpage and data archive: www.physics.purdue.edu/MOJAVE24