Chandra X-Ray Observatory
	(CXC)

Accepted Cycle 11 Observing Proposals

GALACTIC DIFFUSE EMISSION & SURVEYS

Proposal NumberSubject CategoryPI NameTitle
11910040GALACTIC DIFFUSE EMISSION AND SURVEYSMurrayGTO ChIcAGO: Chandra Identification of ASCA Galactic Objects
11910605GALACTIC DIFFUSE EMISSION AND SURVEYSBowerX-Ray Counterparts to Radio Transients
11910648GALACTIC DIFFUSE EMISSION AND SURVEYSFangProbing Galactic Feedback with X-ray Binaries
11910849GALACTIC DIFFUSE EMISSION AND SURVEYSTerrierSgr B2 ten year later: on the nature of the hard X-rays from the CMZ

Subject Category: GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 11910040

Title: GTO ChIcAGO: Chandra Identification of ASCA Galactic Objects

PI Name: Steve Murray

X-ray sources in the Galactic plane trace a variety of exotic populations. Most sources with X-ray fluxes above 1e-11 erg/cm^2/s are well-known objects, while below 1e-13 erg/cm^2/s, AGN, CVs, and active stars dominate. However, many low-latitude sources lie between these two regimes, corresponding to young populations of pulsars, magnetars, hot stars and supernova remnants. To derive the birth-rates, lifetimes and distributions of these relatively rare sources, we propose to localize the unidentified objects in the 60% of the Galactic disk covered by the ASCA Galactic Plane Survey. Combined with archival analyses, multi-wavelength follow-up and the results of previous surveys, this will complete the demography of Galactic X-ray sources, from Sco X-1 down to the faintest sources known.

R.A. Dec. Target Name Det. Grating Exp.Time
14:57:33.00-59:01:18.00AX J145732-5901ACIS-SNONE10
15:10:06.00-58:24:54.00AX J151005-5824ACIS-SNONE10
16:59:05.70-42:07:27.20AX J165901-4208ACIS-SNONE10
18:24:38.10-13:10:47.00AX J182435-1311ACIS-SNONE10
18:33:56.40-08:22:18.60AX J183356-0822ACIS-SNONE10

Subject Category: GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 11910605

Title: X-Ray Counterparts to Radio Transients

PI Name: Geoffrey Bower

The radio transient sky is poorly known. We have recently conducted the most sensitive survey for radio transients (RTs) that has discovered 10 RTs, which have a duration of less than one week, a flaring amplitude of greater than 100, and no identification in deep radio and optical images. These RTs have no clear association with known phenomena. Possible X-ray counterparts to the RTs include isolated neutron stars, active stars, and optically-obscured AGN. An origin with any of these source classes requires a new understanding of event rates and luminosity functions. We propose Chandra ACIS-I observations of this field. Discovery of X-ray counterparts will have a significant impact on our understanding of the processes at work and possibly identify a new source class.

R.A. Dec. Target Name Det. Grating Exp.Time
15:02:20.50+78:16:14.90CAMPBEACIS-INONE50

Subject Category: GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 11910648

Title: Probing Galactic Feedback with X-ray Binaries

PI Name: Taotao Fang

Recent X-ray observations of the Galactic X-ray binaries revealed a number of narrow absorption lines produced by metals in the hot gas; however, it is unclear whether this hot gas is intrinsic to the source, or in the hot interstellar medium, and the answer to this question has fundamental implication in probing Galactic feedback processes. We propose one ToO observation to study X-ray bright sources spatially close to these X-ray binaries. We expect that the hot gas would produce similar absorption if it is ISM in origin. Due to the different intrinsic properties and environment of these X-ray binaries, our observations will offer a clean test of the nature of the hot gas.

R.A. Dec. Target Name Det. Grating Exp.Time
18:35:44.10-32:59:29.00XB 1832-330ACIS-SLETG100
17:08:54.40-32:18:57.504U 1705-32ACIS-SLETG100

Subject Category: GALACTIC DIFFUSE EMISSION AND SURVEYS

Proposal Number: 11910849

Title: Sgr B2 ten year later: on the nature of the hard X-rays from the CMZ

PI Name: Regis Terrier

The origin of the GC molecular clouds 6.4 keV emission has long been a matter of controversy: irradiation by cosmic ray electrons or by X-rays emitted by a flaring source. An interesting candidate in the latter case is a possible 300 yr old flare of Sgr A* of 6 order of magnitude above its current quiescent level. Using 6 years of monitoring of the GC we show a lightcurve of Sgr B2 revealing a significant decrease of the hard X-ray flux with a 20-year timescale, favoring the second scenario. We propose a deep Chandra exposure of Sgr B2 to search for the morphological changes in the cloud emission compared with a similar exposure taken in March 2000. This variations pattern is a key element to finally settle the controversy and understand the actual origin of the likely irradiating source.

R.A. Dec. Target Name Det. Grating Exp.Time
17:47:24.30-28:24:37.10Sgr B2ACIS-INONE100
Smithsonian Institute Smithsonian Institute

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