2011-2012:reasearch
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//Updated with real 2011-2012 stuff// | //Updated with real 2011-2012 stuff// | ||
- | **Gallactic pulsars, variable and transient radio soruces** | + | **Gallactic pulsars, variable and transient radio sources** |
- | JIVE Scientists | + | JIVE scientists |
- | {{2011-2012: | + | {{2011-2012: |
//VLBI images of the transient jets components A, B, C, and the re-activated compact jet D in XTE J1752−233. The bottom panel shows the proper motion versus angular separation for components A and B. All the images are centred at the compact jet (0,0) and rotated clockwise by 39◦. The contours start from 3sigma off-source noise level and increase by a factor of -1, 1, 2, 4. The size of the restoring beam is 10 mas.// | //VLBI images of the transient jets components A, B, C, and the re-activated compact jet D in XTE J1752−233. The bottom panel shows the proper motion versus angular separation for components A and B. All the images are centred at the compact jet (0,0) and rotated clockwise by 39◦. The contours start from 3sigma off-source noise level and increase by a factor of -1, 1, 2, 4. The size of the restoring beam is 10 mas.// | ||
+ | Together with Chinese astronomers from Shanghai (Z. Shen, X. Hong, B. Xia, F. Shu) and Yunnan Astronomical Observatories (Z. Li, Y. Xu), JIVE astronomers (J. Yang/PI, Z. Paragi, L.I. Gurvits, R.M. Campbell) investigated a newly-identified Galactic black hole binary candidate MAXI J1836-194 with the e-EVN and the Chinese VLBI Network. The team successfully detected the low-declination source with a high confidence level in both observations. The source was unresolved, which is in agreement with an AU-scale compact jet (Yang et al. 2012, MNRAS, L66). | ||
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- | Together with Chinese astronomers from Shanghai (Z. Shen, X. Hong, B. Xia, S. Shu) and Yunnan Astronomical Observatories (Z. Li, Y. Xu), JIVE astronomers (J. Yang/PI, Z. Paragi, L.I. Gurvits, R.M. Campbell) investigated a newly-identied Galactic black hole binary candidate MAXI J1836-194 with the e-EVN and the Chinese VLBI Network. The team successfully detected the low-declination source with a high confidence level in both observations. The source was unresolved, which is in agreement with an AU-scale compact jet (Yang et al. ). | + | |
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//VLBI total intensity images of MAXI J1836−194. The synthesized beams are plotted in the bottom left-hand corner. The contours start from 3 sigma off-source noise level (0.54 mJy/beam at 8.3 GHz, 0.24 mJy/beam at 5 GHz) and increase by a factor of 2.// | //VLBI total intensity images of MAXI J1836−194. The synthesized beams are plotted in the bottom left-hand corner. The contours start from 3 sigma off-source noise level (0.54 mJy/beam at 8.3 GHz, 0.24 mJy/beam at 5 GHz) and increase by a factor of 2.// | ||
- | Jun Yang (Co-PI) and Zsolt Pargi observed Nova Mon 2012 in collaboration with Tim O’Brien (PI, University of Manchester, UK) and Laura Chomiuk (NRAO, US). A nova is a cataclysmic nuclear explosion in a white dwarf star. Nova Mon 2012 was first reported as a gamma-ray transient, subsequently associated with an optical nova in Monocerotis. With the real-time e-VLBI observations, | + | Jun Yang (Co-PI) and Zsolt Pargi observed Nova Mon 2012 in collaboration with Tim O’Brien (PI, University of Manchester, UK) and Laura Chomiuk (NRAO, US). A nova is a cataclysmic nuclear explosion in a white dwarf star. Nova Mon 2012 was first reported as a gamma-ray transient, subsequently associated with an optical nova in Monocerotis. With the real-time e-VLBI observations, |
- | {{2011-2012: | + | {{2011-2012: |
- | //The e-EVN total intensity | + | //The e-EVN images of Nova Mon 2012. The contours started from 3-sigma noise level (left: 0.08 mJy/beam, right: 0.12 mJy/beam) and increase by a factor of 2 in each image. Both images have a similar peak brightness ~1.2 mJy/beam. // |
- | Ding Chen (National Space Science Center, China) and Jun Yang observed | + | Ding Chen (National Space Science Center, China) and Jun Yang performed astrometric observations of the bright X-ray millisecond pulsar PSR J0218+4232 during 2011-2012. Currently, all the observations were finished. The final data reduction and astrometry analysis will be started soon. They will report |
**Active Galactic Nuclei** | **Active Galactic Nuclei** | ||
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Working with Fang Wu (ShAO, China) and Tao An (ShAO, China), Jun Yang and Zsolt Paragi imaged the jet in the broad absorption line quasar PG 1700+518. They presented its jet structure on scales of parsec to kiloparsec for the first time (Yang et al. 2012, MNRAS, 419, L74). The source shows two distinct jet features in East-West direction with a separation of around 4 kpc in the VLA image. They identified the radio core and found a symmetric jet morphology in the western jet feature with the EVN observations. The jet axis is nearly parallel to the scattering plane revealed earlier by optical polarimetry. They conclude that the jet likely has a viewing angle around 45 degree by analogy to polar-scattered Seyfert 1 galaxies. Furthermore, | Working with Fang Wu (ShAO, China) and Tao An (ShAO, China), Jun Yang and Zsolt Paragi imaged the jet in the broad absorption line quasar PG 1700+518. They presented its jet structure on scales of parsec to kiloparsec for the first time (Yang et al. 2012, MNRAS, 419, L74). The source shows two distinct jet features in East-West direction with a separation of around 4 kpc in the VLA image. They identified the radio core and found a symmetric jet morphology in the western jet feature with the EVN observations. The jet axis is nearly parallel to the scattering plane revealed earlier by optical polarimetry. They conclude that the jet likely has a viewing angle around 45 degree by analogy to polar-scattered Seyfert 1 galaxies. Furthermore, | ||
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//The VLA and EVN intensity images of PG 1700+518. The contours start from 3σ off-source noise level (VLA: 0.036 mJy/beam, EVN: 0.15 mJy/beam) and increase by a factor of 2. // | //The VLA and EVN intensity images of PG 1700+518. The contours start from 3σ off-source noise level (VLA: 0.036 mJy/beam, EVN: 0.15 mJy/beam) and increase by a factor of 2. // | ||
- | Jun Yang, Zsolt Paragi, Leonid Gurvits, Robert M. Campbell, and Alexander van der Horst (University of Amsterdam) have initiated a campaign in directly observing the motion of the relativistic jet in Swift J1644+57 | + | Jun Yang, Zsolt Paragi, Leonid Gurvits, Robert M. Campbell, and Alexander van der Horst (University of Amsterdam) have initiated a campaign in directly observing the motion of the relativistic jet in the tidal disruption event Swift J1644+57. Currently, they have observed the transient AGN at four epochs. The preliminary results show that a position precision of ~15 micro-arcseconds |
{{2011-2012: | {{2011-2012: | ||
- | //The EVN phase-referencing observations of Swift J1644+57 and its in-beam calibrator FIRST J1644+5736 (a separation of 2.8 arcmin). The background | + | //The EVN phase-referencing observations of Swift J1644+57 and its in-beam calibrator FIRST J1644+5736 (a separation of 2.8 arcmin). The background |
2011-2012/reasearch.txt · Last modified: 2013/02/28 13:23 by yang