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 deg² 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 10³² and ~8 x 10³² 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 CDS Catalog J/ApJ/825/132 files table2.dat, table3.dat, table4.dat and table5.dat. This is a service provided by NASA HEASARC .

This table contains some of the science results from the Nuclear Spectroscopic Telescope Array (NuSTAR) Serendipitous Survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ~20 Ms of effective exposure time over 331 fields, with an areal coverage of 13 deg². The primary catalog (available as the HEASARC NUSTARSSC table) contains 498 sources (the abstract of the reference paper states that there are 497 sources) detected in total over the 3-24 keV energy range. There are 276 sources with spectroscopic redshifts and classifications, largely resulting from the authors' extensive campaign of ground-based spectroscopic follow-up. The authors characterize the overall sample in terms of the X-ray, optical, and infrared source properties. The sample is primarily composed of active galactic nuclei (AGN), detected over a large range in redshift from z = 0.002 to 3.4 (median redshift z of 0.56), but also includes 16 spectroscopically confirmed Galactic sources. There is a large range in X-ray flux, from log (f_3-24_keV) ~ -14 to -11 (in units of erg s^-1 cm^-2), and in rest-frame 10-40 keV luminosity, from log (L_10-40keV) ~ 39 to 46 (in units of erg s^-1), with a median of 44.1. Approximately 79% of the NuSTAR sources have lower-energy (<10 keV) X-ray counterparts from XMM-Newton, Chandra, and Swift XRT observations. The mid-infrared (MIR) analysis, using WISE all-sky survey data, shows that MIR AGN color selections miss a large fraction of the NuSTAR-selected AGN population, from ~15% at the highest luminosities (L_X > 10⁴⁴ erg s^-1) to ~80% at the lowest luminosities (L_X < 10⁴³ erg s^-1). The authors' optical spectroscopic analysis finds that the observed fraction of optically obscured AGN (i.e., the type 2 fraction) is F_Type2 = 53 (+14, -15) per cent, for a well-defined subset of the 8-24 keV selected sample. This is higher, albeit at a low significance level, than the type 2 fraction measured for redshift- and luminosity-matched AGNs selected by < 10 keV X-ray missions. This table contains the Secondary NuSTAR Serendipitous Source Catalog of 64 sources found using wavdetect to search for significant emission peaks in the FPMA and FPMB data separately (see Section 2.1.1 of Alexander et al. 2013, ApJ, 773, 125) and in the combined A+B data. These sources are listed in Table 7 of the reference paper. This method was developed alongside the primary one (Section 2.3 of the reference paper) in order to investigate the optimum source detection methodologies for NuSTAR and to identify sources in regions of the NuSTAR coverage that are automatically excluded in the primary source detection. The authors emphasize that these secondary sources are not used in any of the science analyses presented in their paper. Nevertheless, these secondary sources are robust NuSTAR detections, some of which will be incorporated in future NuSTAR studies, and for many of them (35 out of the 43 sources with spectroscopic identifications) the authors have obtained new spectroscopic redshifts and classifications through their follow-up program. The X-ray photometric parameters for 4 sources are left blank as in these cases the A+B data prohibit reliable photometric constraints. Additional information on these Secondary Catalog sources that the authors obtained using optical spectroscopy is available in Table 8 of the reference paper (q.v.). This table does NOT contain the the 498 sources in the Primary NuSTAR Serendipitous Source Catalog that were found using the source detection procedure described in Section 2.3 of the reference paper, and that are listed in Table 5 (op. cit.). This table was created by the HEASARC in July 2017 based on the machine-readable version of Table 7 from the reference

This table contains the first full catalog and science results for the Nuclear Spectroscopic Telescope Array (NuSTAR) Serendipitous Survey. The catalog incorporates data taken during the first 40 months of NuSTAR operation, which provide ~20 Ms of effective exposure time over 331 fields, with an areal coverage of 13 deg², and 498 sources (the abstract of the reference paper states that there are 497 sources) detected in total over the 3-24 keV energy range. There are 276 sources with spectroscopic redshifts and classifications, largely resulting from the authors' extensive campaign of ground-based spectroscopic follow-up. The authors characterize the overall sample in terms of the X-ray, optical, and infrared source properties. The sample is primarily composed of active galactic nuclei (AGN), detected over a large range in redshift from z = 0.002 to 3.4 (median redshift z of 0.56), but also includes 16 spectroscopically confirmed Galactic sources. There is a large range in X-ray flux, from log (f_3-24keV) ~ -14 to -11 (in units of erg s^-1 cm^-2), and in rest-frame 10-40 keV luminosity, from log (L_10-40keV) ~ 39 to 46 (in units of erg s^-1), with a median of 44.1. Approximately 79% of the NuSTAR sources have lower-energy (<10 keV) X-ray counterparts from XMM-Newton, Chandra, and Swift XRT observations. The mid-infrared (MIR) analysis, using WISE all-sky survey data, shows that MIR AGN color selections miss a large fraction of the NuSTAR-selected AGN population, from ~15% at the highest luminosities (L_X > 10⁴⁴ erg s^-1) to ~80% at the lowest luminosities (L_X < 10⁴³ erg s^-1). The authors' optical spectroscopic analysis finds that the observed fraction of optically obscured AGN (i.e., the type 2 fraction) is F_Type 2_ = 53 (+14, -15) per cent, for a well-defined subset of the 8-24 keV selected sample. This is higher, albeit at a low significance level, than the type 2 fraction measured for redshift- and luminosity-matched AGNs selected by <10 keV X-ray missions. This table contains the Primary NuSTAR Serendipitous Source Catalog of 498 sources found using the source detection procedure described in Section 2.3 of the reference paper, and listed in Table 5 (op. cit.). Additional information on these Primary Catalog sources that the authors obtained using optical spectroscopy is available in Table 6 of the reference paper (q.v.). This table does not contain the 64 sources in the Secondary NuSTAR Serendipitous Source Catalog that were found using wavdetect and that are listed in Table 7 of the reference paper: this is available in the HEASARC database as a separate table, dubbed NUSTARSSC2. This table was created by the HEASARC in July 2017 based on the machine-readable version of Table 5 from the reference paper, the Primary NuSTAR Serendipitous Source Catalog, that was obtsined from the ApJ web site. This is a service provided by NASA HEASARC .

This table contains the source catalog from the Nuclear Spectroscopic Telescope Array (NuSTAR) survey of the Extended Chandra Deep Field South (hereafter, ECDFS), that is currently the deepest contiguous component of the NuSTAR extragalactic survey program. The survey covers the full ~30' x 30' area of this field to a maximum depth of ~360 ks (~220 ks when corrected for vignetting at 3 - 24 keV), reaching sensitivity limits of ~1.3 x 10^-14 erg/s/cm² (3 - 8 keV), ~3.4 x 10^-14 erg/s/cm² (8 - 24 keV), and ~3.0 x 10^-14 erg/s/cm² (3 - 24 keV). A total of 54 sources are detected over the full field, although five of these are found to lie below our significance threshold once contaminating flux from neighboring (i.e., blended) sources is taken into account. Of the remaining 49 that are significant, 19 are detected in the 8 - 24 keV band. The 8 - 24 to 3 - 8 keV band ratios of the 12 sources that are detected in both bands span the range 0.39 - 1.7, corresponding to a photon index (Gamma) range of about 0.5 - 2.3, with a median photon index of 1.70 +/- 0.52. The redshifts of the 49 sources in the main sample span the range z = 0.21 - 2.7, and their rest-frame 10 - 40 keV luminosities (derived from the observed 8 - 24 keV fluxes) span the range L_10-40keV ~ (0.7 - 300) x 10⁴³erg/s, sampling below the "knee" of the X-ray luminosity function out to z ~ 0.8 - 1. Finally, the authors identify one NuSTAR source that has neither a Chandra nor an XMM-Newton counterpart, but that shows evidence of nuclear activity at infrared wavelengths and thus may represent a genuine, new X-ray source detected by NuSTAR in the ECDFS. The NuSTAR ECDFS survey consists of observations from two separate passes. Observations making up the first pass were taken between 2012 September and December, and those making up the second pass were taken roughly six months later, between 2013 March and April. For their cosmological calculations, the authors adopt a Hubble constant H₀ of 71 km s^-1 Mpc ^-1, Omega_M of 0.27, and Omega_Lambda of 0.73. This table was created by the HEASARC in September 2017 based on the CDS Catalog J/ApJ/808/184 file catalog.dat. This is a service provided by NASA HEASARC .

 53 = [OI81] 14 = [MJD95] 104; spectral type B1V; pmRA=11.0 mas/yr, pmDE=-2.8 mas/yr; 54 = [OI81] 10 = [MJD95] 108; spectral type B2V; pmRA=-2.3 mas/yr, pmDE=-11.9 mas/yr; 61 = V539 Mon [OI81] 13 = [MJD95] 110; MSX6C G206.1821-02.3456; pmRA=2.8 mas/yr, pmDE=0.4 mas/yr; 71 = [OI81] 12 = [MJD95] 102; pmRA=6.8 mas/yr, pmDE=0.6 mas/yr; 128 = [OI81] 35 = [MJD95] 471; spectral type A2:; pmRA=-0.8 mas/yr, pmDE=3.6 mas/yr; 138 = [OI81] 36 = [MJD95] 497; spectral type B5; pmRA=6.5 mas/yr, pmDE=2.1 mas/yr; 141 = [MJD95] 498; pmRA=-3.0 mas/yr, pmDE=1.9 mas/yr; 149 = [BC02] 11; known X-ray source; log(Lx(ROSAT/PSPC))=31.01 erg/s; pmRA=0.6 mas/yr, pmDE=-12.6 mas/yr; 161 = [MJD95] 653; pmRA=-1.0 mas/yr, pmDE=-5.4 mas/yr 

With the goal of improving the member census of the NGC 2264 star-forming region and studying the origin of X-ray activity in young pre-main sequence (PMS) stars, the authors analyzed a deep, 100 ks long, Chandra ACIS observation covering a 17' x 17' field in the 3 Myr old star-forming region (SFR) NGC 2264. The preferential detection in X-rays of low-mass PMS stars gives strong indications of their membership. The authors study X-ray activity as a function of stellar and circumstellar characteristics by correlating the X-ray luminosities, temperatures, and absorptions with optical and near-infrared (NIR) data from the literature. The authors detected 420 X-ray point sources in the observation above a 4.6-sigma significance threshold using the PWDetect software. Optical and NIR counterparts were found in the literature for 85% of the sources. The authors argue that more than 90% of these counterparts are NGC 2264 members, thereby significantly increasing the known low-mass cluster population by about 100 objects. Among the sources without counterpart, about 50% are probably associated with members, several of which are expected to be previously unknown protostellar objects. With regard to activity, several previous findings are confirmed: X-ray luminosity is related to stellar mass, although with a large scatter; L_x/L_bol is close to, but almost invariably below, the saturation level of 10^-3, especially when considering the quiescent X-ray emission. A comparison between classical T Tauri stars (CTTS) and weak-line T Tauri stars (WTTS) shows several differences: CTTS have, at any given mass, activity levels that are both lower and more scattered than WTTS; emission from CTTS may also be more time variable and is on average slightly harder than for WTTS. However, there is evidence in some CTTS of extremely cool, ~0.1 - 0.2 keV, plasma which the authors speculate is due to plasma heated by accretion shocks. The X-ray spectra of the 199 sources with more than 50 detected photons were analyzed by the authors. Spectral fits were performed with XSPEC 11.3 and with several shell and TCL scripts to automate the process. For each source, they fit the data in the [0.5 - 7.0] keV energy interval with several model spectra: one and two isothermal components (APEC), subject to photoelectric absorption from interstellar and circumstellar material (WABS). Plasma abundances for one-temperature (1T) models were fixed at 0.3 times the solar abundances, while they were both fixed at that value and treated as a free parameter for the two-temperature (2T) models. The absorbing column densities, N_H, were both left as a free parameter and fixed at values corresponding to the optically/NIR determined extinctions, when available: N_H = 1.6 x 10²¹ A_V. This table contains the X-ray, optical and NIR data for the 420 detected X-ray sources; it does not contain the master catalog of 1598 optical/NIR sources within the ACIS FOV which was presented in Table 3 of the reference paper, available at https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/455/903/table3.dat This table was created by the HEASARC in March 2007 based on CDS Catalog J/A+A/455/903 files table1.dat, table4.dat and table6.dat. This is a service provided by NASA HEASARC .

This table contains the results from a deep X-ray survey of the young (~ 140 Myr), rich open cluster NGC 2516 obtained with the EPIC camera on board the XMM-Newton satellite. By combining the data from six observations, a high sensitivity, greater than a factor of 5 with respect to recent Chandra observations, has been achieved. Kaplan-Meier estimators of the cumulative X-ray luminosity distribution, statistically corrected for non-member contaminants, were built by the authors and compared to those of the nearly coeval Pleiades cluster. 431 X-ray sources were detected, and 234 of them have as optical counterparts cluster stars spanning the entire NGC 2516 main sequence. On the basis of X-ray emission and optical photometry, 20 new candidate members of the cluster have been identified; at the same time there are 49 X-ray sources without known optical or infrared counterpart. The X-ray luminosities of cluster stars span the range log L_x (erg s^-1) = 28.4 - 30.8. The representative coronal temperatures span the 0.3 - 0.6 keV (3.5 - 8 MK) range for the cool component and 1.0 - 2.0 keV (12 - 23 MK) for the hot one; similar values were found in other young open clusters like the Pleiades, IC 2391, and Blanco 1. While no significant differences were found in their X-ray spectra, NGC 2516 solar-type stars are definitely less luminous in X-rays than their nearly coeval Pleiades counterparts. The comparison with a previous ROSAT survey reveals the lack of variability amplitudes larger than a factor of 2 in solar-type cluster stars in a ~ 11 yr time scale, and thus activity cycles like in the Sun are probably absent or have a different period and amplitude in young stars. NGC 2516 has been observed several times with XMM-Newton during the first two years of satellite operations for calibration purposes. The observations used in this analysis span a period of 19 months with exposure times between 10 and 20 ks. All of these observations have been performed with the thick filter. In the combined EPIC datasets the authors detected 431 X-ray sources with a significance level greater than 5.0 sigma, which should lead statistically to at most one spurious source in the field of view. This table was created by the HEASARC in May 2007 based on CDS catalog J/A+A/450/993 files tablea1.dat and tableb1.dat. This is a service provided by NASA HEASARC .

This table contains the source catalog from a new Chandra ACIS-I observation of the nearby (2.0 Mpc) SA(s)d spiral galaxy NGC 300 which was obtained as part of the Chandra Local Volume Survey (CLVS). This 63-ks exposure covers ~88% of the D₂₅ isophote (R ~ 6.3 kpc) and yields a catalog of 95 X-ray point sources detected at high significance down to a limiting unabsorbed 0.35-8 keV luminosity of ~ 10³⁶ erg/s. Sources were cross-correlated with a previous XMM-Newton catalog, and the authors find 75 "X-ray transient candidate" sources that were detected by one observatory, but not the other. They derive an X-ray scale length of 1.7 +/- 0.2 kpc and a recent star formation rate of 0.12 M_sun/yr in excellent agreement with optical observations. Deep, multi-color imaging from the Hubble Space Telescope, covering ~ 32% of this Chandra field, was used to search for optical counterparts to the X-ray sources, and the authors have developed a new source classification scheme to determine which sources are likely X-ray binaries, supernova remnants, and background active galactic nucleus candidates. In the reference paper, the authors present the X-ray luminosity functions (XLFs) at different X-ray energies, and find the total NGC 300 X-ray point-source population to be consistent with other late-type galaxies hosting young stellar populations (<~ 50 Myr). They find that the XLF of sources associated with older stellar populations has a steeper slope than the XLF of X-ray sources coinciding with young stellar populations, consistent with theoretical predictions. NGC 300 was observed on 2010 September 25 for 63 ks using ACIS-I during the Chandra X-Ray Observatory Cycle 12, observation ID 12238. The source detection strategy that was used is described in Section 2.3 of the reference paper. ACIS-Extract (AE) was run a final time on the source list that was produces after an initial run of wavdetect followed by several iterations of AE, and the Poisson probability of not being a source (pns) value was computed in each of the following nine energy bands: 0.5 - 8.0, 0.5 - 2.0, 2.0 - 8.0, 0.5 - 1.0, 1.0 - 2.0, 2.0 - 4.0, 4.0 - 8.0, 0.35 - 1.0 and 0.35 - 8.0 keV. To be included in the final NGC 300 catalog, a source was required to have a pns value less than 4 x 10^-6 in any of the nine energy bands; if only the 0.35 - 8 keV band were considered, ~4% of significant sources would have been lost. The final CLVS source catalog for NGC 300 contains 95 sources. This table was initially created by the HEASARC in September 2014 based on CDS Catalog J/ApJ/758/15/ files table4.dat, table5.dat, table6.dat and table7.dat containing the X-ray properties of the 95 Chandra point sources found in this study. The information on the optical counterparts to (some of) the Chandra X-ray sources and on the X-ray point source classification (presented in Tables 16 and 17, respectively, of the reference paper) is not included herein. It was updated in September 2015 to include the unabsorbed 0.35-8.0 keV energy fluxes (in the parameter herein called b4_flux) from the second reference paper. This is a service provided by NASA HEASARC .