scholarly journals Near IR Astrometry of Magnetars

2012 ◽  
Vol 8 (S291) ◽  
pp. 514-516
Author(s):  
Shriharsh P. Tendulkar

AbstractWe report on the progress of our five-year program for astrometric monitoring of magnetars using high-resolution NIR observations using the laser guide star adaptive optics (LGS-AO) supported NIRC2 camera on the 10-meter Keck telescope. We have measured the proper motion of two of the youngest magnetars, SGR 1806–20 and SGR 1900+14, which have counterparts with K ~21 mag, and have placed a preliminary upper limit on the motion of the young AXP 1E 1841–045. The precision of the proper motion measurement is at the milliarcsecond per year level. Our proper motion measurements now provide evidence to link SGR 1806–20 and SGR 1900+14 with neighboring young star clusters. At the distances of these magnetars, their proper motion corresponds to transverse space velocities of 350 ± 100 km s−1 and 130 ± 30 km s−1 respectively. The upper limit on the proper motion of AXP 1E 1841–045 is 160 km s−1. With the sample of proper motions available, we conclude that the kinematics of the magnetar family are not distinct from that of pulsars.

2008 ◽  
Vol 675 (2) ◽  
pp. 1278-1292 ◽  
Author(s):  
A. Stolte ◽  
A. M. Ghez ◽  
M. Morris ◽  
J. R. Lu ◽  
W. Brandner ◽  
...  

2013 ◽  
Vol 9 (S303) ◽  
pp. 264-268 ◽  
Author(s):  
L. Meyer ◽  
A. M. Ghez ◽  
G. Witzel ◽  
T. Do ◽  
K. Phifer ◽  
...  

AbstractWe give an update of the observations and analysis of G2 – the gaseous red emission-line object that is on a very eccentric orbit around the Galaxy's central black hole and predicted to come within 2400 RS in early 2014. During 2013, the laser guide star adaptive optics systems on the W. M. Keck I and II telescopes were used to obtain three epochs of spectroscopy and imaging at the highest spatial resolution currently possible in the near-IR. The updated orbital solution derived from radial velocities in addition to Br-γ line astrometry is consistent with our earlier estimates. Strikingly, even ∼ 6 months before pericenter passage there is no perceptible deviation from a Keplerian orbit. We furthermore show that a proposed “tail” of G2 is likely not associated with it but is rather an independent gas structure. We also show that G2 does not seem to be unique, since several red emission-line objects can be found in the central arcsecond. Taken together, it seems more likely that G2 is ultimately stellar in nature, although there is clearly gas associated with it.


1997 ◽  
Vol 23 (1) ◽  
pp. 498-514 ◽  

During the period covered by this report, major progresses have been achieved in various fields of astronomical techniques and instruments. The era of large telescopes has been opened with the commissioning of the 2 Keck telescopes and the final construction phase for major facilities (ESO, JNLT, LBT, Gemini, etc). More than ten telescopes, with aperture larger than 8m, will be ready to scrutinize the sky, at the beginning of the next century. A Spanish project (GRANTBCAN) remains incompletely financed at this time. The power of these telescopes will be maximum when full diffraction limit capabilities will be available at their focus. The period 1994-1997 has seen major and spectacular achievements with realisation of several operationnal adaptative optic systems on 4m-class telescopes (ESO, CFHT). Diffraction limits have been reached at near-IR wavelength and partial correction, even in the visible, are bringing resolution comparable to space observations. All 8-10m projects require adaptative optics and have plans for it. In the meantime, 3-4m class telescopes are beeing equiped as well, so that AO will appear everywhere within the next 3 years. The necessary complement of adaptive optics, ie: the laser guide star, is thoroughly studied in order to provide full coverage for atmospheric compensation all over the sky. Projects of monochromatic and polychromatic laser stars are flourishing in relation with all telescopes with aperture of 3m-plus adaptative optics projects. Field coverage and achievable resolution require good pixel sampling and therefore large format detectors. Projects of very large format cameras for the visible and infrared are considered, up to 16kxl6k (MEGACAM at CFHT for 1.5 degrees field). Progress has been obtained in the industry to reduce gaps in between bootable CCDs, to reduce amplifiers noise and improve sensitivity. High angular resolution capabilities will gain another magnitude when the actual developments on interferometry with small telescopes will be tranfered to arrays of large telescopes (ESO, Keck, etc). Resolutions of 0.001 arc. sec will be available within 5 years leading to a gain of a factor 1000 compared to a 3.5m telescope operating today without adaptive optics.


2012 ◽  
Vol 751 (2) ◽  
pp. 132 ◽  
Author(s):  
W. I. Clarkson ◽  
A. M. Ghez ◽  
M. R. Morris ◽  
J. R. Lu ◽  
A. Stolte ◽  
...  

2007 ◽  
Vol 15 (8) ◽  
pp. 4711 ◽  
Author(s):  
Richard M. Clare ◽  
Marcos A. van Dam ◽  
Antonin H. Bouchez

2003 ◽  
Vol 400 (3) ◽  
pp. 1199-1207 ◽  
Author(s):  
R. C. Flicker ◽  
F. J. Rigaut ◽  
B. L. Ellerbroek

1998 ◽  
Author(s):  
Claire E. Max ◽  
Bruce A. Macintosh ◽  
Scot S. Olivier ◽  
Donald T. Gavel ◽  
Herbert W. Friedman

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