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Resource Record Summary

Catalog Service:
NuSTAR Hard X-Ray Survey of the Galactic Center

Short name: NUGALCEN
IVOA Identifier: ivo://nasa.heasarc/nugalcenPublisher: NASA/GSFC HEASARCivo://nasa.heasarc/ASD[Pub. ID]
More Info: https://heasarc.gsfc.nasa.gov/W3Browse/all/nugalcen.html
VO Compliance: Level 2: This is a VO-compliant resource.
Status: active
Registered: 2024 Sep 20 00:00:00Z
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Description


This table contains some of the the first survey results of hard X-ray point sources in the Galactic Center (GC) region obtained by NuSTAR. The authors have discovered 70 hard (3-79 keV) X-ray point sources in a 0.6 deg<sup>2</sup> region around Sgr A* with a total exposure of 1.7 Ms, and 7 sources in the Sgr B2 field with 300 ks. They identify clear Chandra counterparts for 58 NuSTAR sources and assign candidate counterparts for the remaining 19. The NuSTAR survey reaches X-ray luminosities of ~4 x 10<sup>32</sup> and ~8 x 10<sup>32</sup> erg/s at the GC (8 kpc) in the 3-10 and 10-40 keV bands, respectively. The source list includes three persistent luminous X-ray binaries (XBs) and the likely run-away pulsar called the Cannonball. New source-detection significance maps reveal a cluster of hard (>10 keV) X-ray sources near the Sgr A diffuse complex with no clear soft X-ray counterparts. The severe extinction observed in the Chandra spectra indicates that all the NuSTAR sources are in the central bulge or are of extragalactic origin. Spectral analysis of relatively bright NuSTAR sources suggests that magnetic cataclysmic variables constitute a large fraction (>40% - 60%). Both spectral analysis and logN - logS distributions of the NuSTAR sources indicate that the X-ray spectra of the NuSTAR sources should have kT > 20 keV on average for a single-temperature thermal plasma model or an average photon index of Gamma = 1.5 - 2 for a power-law model. These findings suggest that the GC X-ray source population may contain a larger fraction of XBs with high plasma temperatures than the field population. The observations of the GC region with NuSTAR began in 2012 July, shortly after its launch. The original survey strategy for the GC region was to match the central 2 degree x 0.7 degree region covered by the Chandra X-ray Observatory (Wang et al. 2002, Nature, 415, 148; Muno et al. 2009, ApJS, 181, 110). The field of views (FOVs) of neighboring NuSTAR observations in the survey were designed to overlap with each other by ~40%. Multiple observations of the same region with relatively large FOV offsets tend to average out the vignetting effects of each observation, enabling a more uniform coverage of the region. Multiple observations are also suitable for monitoring long term X-ray variability of sources in the region. Even when observing a single target, the NuSTAR observation is often broken up into two or more segments with relatively large pointing offsets to allow an efficient subtraction of a detector coordinate-dependent background component (e.g., Mori et al. 2013, ApJ, 770, L23). This table was created by the HEASARC in March 2018, based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/825/132">CDS Catalog J/ApJ/825/132</a> files table2.dat, table3.dat, table4.dat and table5.dat. This is a service provided by NASA HEASARC .

More About this Resource

About the Resource Providers

This section describes who is responsible for this resource

Publisher: NASA/GSFC HEASARCivo://nasa.heasarc/ASD[Pub. ID]

Creator: Hong et al. Contributor:

Contact Information:
X NASA/GSFC HEASARC help desk
Email:

Status of This Resource

This section provides some status information: the resource version, availability, and relevant dates.

Version: n/a
Availability: This is an active resource.
  • This service apparently provides only public data
Relevant dates for this Resource:
  • Representative: 2024 Sep 20

This resource was registered on: 2024 Sep 20 00:00:00Z
This resource description was last updated on: 2024 Sep 20 00:00:00Z

What This Resource is About

This section describes what the resource is, what it contains, and how it might be relevant.

Resource Class: CatalogService
This resource is a service that provides access to catalog data. You can extract data from the catalog by issuing a query, and the matching data is returned as a table.
Resource type keywords:
  • Catalog
Subject keywords:
  • Survey Source
This service provides data from:
  • facility: NUSTAR
Intended audience or use:
  • Research: This resource provides information appropriate for supporting scientific research.
More Info: https://heasarc.gsfc.nasa.gov/W3Browse/all/nugalcen.html Literature Reference: 2016ApJ...825..132H

Related Resources:

Services that provide access to data in this resource:
HEASARC TAP ivo://nasa.heasarc/services/xamin [Res. ID]

Data Coverage Information

This section describes the data's coverage over the sky, frequency, and time.

Reference Coordinate System: UTC-ICRS-TOPOXXivo://STClib/CoordSys#UTC-ICRS-TOPO[Res. ID]

Sky Coverage: Regions covered:

  • All-sky: The data from this resource is distributed over the entire sky.
Typical Size Scale (Region of Regard): , 0.0333333333333333 deg

Wavebands covered:

  • X-ray

Available Service Interfaces

Simple Cone SearchXXSearch Me

This is a standard IVOA service that takes as input a position in the sky and a radius and returns catalog records with positions within that radius.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for the standard interface:
  • https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=nugalcen&
Maximum search radius accepted: 180 degrees
Maximum number of matching records returned: 99999
This service supports the VERB input parameter:
Use VERB=1 to minimize the returned columns or VERB=3 to maximize.
Table Access Protocol - Auxiliary ServiceXX

This is a standard IVOA service that takes as input an ADQL or PQL query and returns tabular data.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for the standard interface:
  • https://heasarc.gsfc.nasa.gov/xamin/vo/tap
Custom Service

This is service that does not comply with any IVOA standard but instead provides access to special capabilities specific to this resource.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for this service interface:
  • URL-based interface: https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=nugalcen
Custom Service

This is service that does not comply with any IVOA standard but instead provides access to special capabilities specific to this resource.

VO Compliance: Level 2: This is a VO-compliant resource.
Available endpoints for this service interface:


Developed with the support of the National Science Foundation
under Cooperative Agreement AST0122449 with the Johns Hopkins University
The NAVO project is a member of the International Virtual Observatory Alliance

This NAVO Application is hosted by the Space Telescope Science Institute

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