NUAFTL Catalog
The NUAFTL database table records the As-Flown Timeline for the Nuclear
Spectroscopic Telescope Array (NuSTAR) hard X-ray observatory. NuSTAR
observes the sky in the high energy X-ray (3 - 79 keV) region of the
electromagnetic spectrum using focusing optics. The as-flown timeline
provides a summary of what NuSTAR has observed and is updated automatically
when each observation is completed.
NUCOSMOSFC Catalog
To provide the census of the sources contributing to the X-ray background
peak above 10 keV, the Nuclear Spectroscopic Telescope Array (NuSTAR) is
performing extragalactic surveys using a three-tier "wedding cake" approach.
In their paper, the authors present the NuSTAR survey of the COSMOS field,
the medium sensitivity, and medium area "tier",covering 1.7 deg2 and
overlapping with both Chandra and XMM-Newton data. This survey consists of
121 NuSTAR observations for a total exposure of ~3 Ms. To fully exploit these
data, the authors developed a new detection strategy, carefully tested
through extensive simulations. The survey sensitivity at 20% completeness is
5.9, 2.9, and 6.4 x 10-14 erg cm-2 s-1 in the 3-24, 3-8 and 8-24 keV
bands, respectively. By combining detections in 3 bands, the survey consists
of a sample of 91 NuSTAR sources with luminosities ~ 1042 - 1045.5 erg
s-1and redshifts z ~ 0.04-2.5. Thirty-two sources are detected in the 8-24
keV band with fluxes ~100 times fainter than sources detected by Swift-BAT.
Of the 91 detections, all but 4 are associated with a Chandra and/or
XMM-Newton point-like counterpart. One source is associated with an extended
lower energy X-ray source. The authors present the X-ray (hardness ratio and
luminosity)and optical-to-X-ray properties. The observed fraction of
candidate Compton-thick active galactic nuclei measured from the hardness
ratio is between 13% - 20%. In their paper, the authors discuss the spectral
properties of the source named NuSTAR J100259+0220.5 (source number 330) at a
redshift z = 0.044, which has the highest hardness ratio in the entire
sample. The measured column density exceeds 1024 cm-2, implying the
source is Compton-thick. This source was not previously recognized as such
without the data at energies >10 keV.
NUECDFSCAT Catalog
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 L10-40keV ~ (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, OmegaM of 0.27, and OmegaLambda of 0.73.
NUGALCEN Catalog
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).
NUMASTER Catalog
The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012
June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR
operates in the band from 3 to 79 keV, extending the sensitivity of focusing
instruments far beyond the ~10 keV high-energy cutoff achieved by all
previous X-ray satellites. The inherently low background associated with
concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with
a more than 100-fold improvement in sensitivity over the collimated or coded
mask instruments that have operated in this bandpass. The observatory was
placed into a 600-km altitude, 6 degree inclination circular orbit, and
consists of two co-aligned grazing-incidence X-ray telescopes pointed at
celestial targets by a three-axis stabilized spacecraft. NuSTAR has completed
its two-year primary science mission, and, with an expected orbit lifetime of
more than 10 years, the opportunity for proposing observations as part of the
General Observer (GO) program is now available, with observations beginning
in 2015.
Using its unprecedented combination of sensitivity and spatial and spectral
resolution, NuSTAR offers opportunities for a broad range of science
investigations, ranging from probing cosmic ray origins to studying the
extreme physics around compact objects to mapping micro-flares on the surface
of the Sun. NuSTAR also responds to targets of opportunity including
supernovae and gamma-ray bursts.
This table contains a list of (a) unobserved targets that are planned or have
been accepted for observation by NuSTAR in the future and (b) NuSTAR
observations which have been processed and successfully validated by the
NuSTAR Science Operation Center. The data from these observations may or may
not be public and the user should check the value of the public_date
parameter to determine the status of a specified data set. Only those ObsIDs
which have a public_date in the past will have data publicly available.
Observations with a public_date parameter value which is either blank or a
date in the future have been ingested into the HEASARC archive but will
remain encrypted until their public date. Entries with the status field set
to 'accepted' are targets approved for scheduling, and the planned exposure
time given in the exposure_a (and exposure_b) parameter will have a negative
value for those targets.
NUSTARSSC Catalog
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 (f3-24keV) ~ -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 (LX > 1044 erg s-1)
to ~80% at the lowest luminosities (LX < 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.
NUSTARSSC2 Catalog
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 (L10-40keV) ~ 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 (LX >
1044 erg s-1) to ~80% at the lowest luminosities (LX < 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 FType2 =
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.).
