JACPOT XRB 2010-2011 status

JACPOT XRB is a Target of Opportunity project, to be triggered by a detection of an outburst with an X-ray satellite (RXTE, SWIFT, INTEGRAL or MAXI), or, for the white dwarf system, on an AAVSO alert. On receipt of an alert, we will immediately begin monitoring with the VLA (northern hemisphere) or ATCA (southern hemisphere), and on detection of radio emission, the VLBA (nothern hemisphere) or LBA (southern hemisphere) will begin its monitoring campaign.

In 2009-2010, we monitored a white dwarf (SS Cyg), a neutron star (Aql X-1), and a black hole (H1743-322). In 2010-2011, we monitored a black hole system (MAXI J1836-194), as our target neutron star proved (4U 1820-30) too faint for VLBA monitoring. For the 2012-2013 campaign, we triggered VLA observations of a black hole system (Swift J1745-26); however, high telescope demand prevented VLBA monitoring. We are currently allocated time to monitor a black hole source in the northern hemisphere and southern hemisphere during 2013-2014.

2010-2011 Black Hole Status:
Triggered on Aug 2011 Flare of MAXI J1836-194

  • 29-Aug-2011: MAXI detects new transient source (Negoro et al., ATel 3611).
  • 31-Aug-2011: MAXI detects a spectral transition from hard intermediate to soft intermediate state (Nakahira et al. ATel 3626).
  • 03-Sep-2011: JACPOT XRB triggered EVLA observations successfully detect unresolved radio activity at 4.6 & 7.9 GHz of 26.9±0.1 & 39.6±0.1 mJy (Miller-Jones et al., ATel 3628). Source position is RA (J2000) = 18:35:43.44587 ± 0.00009, Dec (J2000) = -19:19:10.462 ± 0.002. EVLA/VLBA observations ongoing.
  • 04-Sep-2011: First JACPOT XRB observations of MAXI J1836-194 with the VLBA. Source detected at both 8.4 and 2.3 GHz. Marginally-resolved compact jets seen at the higher frequency.
  • 18-Sep-2011: JACPOT XRB EVLA observations detect polarized emission from MAXI J1836-194.
  • 23-Sep-2011: RATAN-600 provide daily 4.8-GHz light curves from 2-22 September (Trushkin et al., ATel 3656).
  • 18-Oct-2011: Russell et al. report 2-12 micron detections of MAXI J1836-194 with VISIR on the VLT (ATel 3689).
  • 18-Oct-2011: Final JACPOT XRB observations taken with VLBA. Proper motion of binary system detected.
  • 01-Dec-2011: MAXI J1836-194 gets too close to the Sun for further X-ray observations; RXTE and Swift observations cease.
  • 03-Dec-2011: Final JACPOT XRB EVLA observation taken.

2010-2011 Neutron Star Status:
Triggered on 4U1820-30

Initial EVLA observations showed the source to be too faint for a VLBA campaign (0.1 mJy), so the observation campaign was halted.

2009-2010 Statuses:
All Triggered & Archived Here