NuSTAR Bringing the High Energy Universe into Focus

 

Legacy Surveys

NuSTAR will continue both Galactic and Extragalactic Legacy Surveys during the extended mission, with programs selected based on community input. The legacy surveys listed below have been chosen to be observed during the extended mission (2015-2018).

Last updated: 2017/11/03


Why Legacy Surveys?

Two of NuSTAR’s key mission goals were to conduct deep, wide-field surveys in both Galactic and extragalactic fields. While a significant amount of time has already been invested in these surveys during the baseline mission, it is clear that maximizing the legacy of the NuSTAR satellite will require significantly extending both of these surveys.


Legacy Surveys in Action

The Legacy Survey programs have been designed in consultation with the community, while the detailed observations are planned, scheduled, and executed by the NuSTAR science team. This team has the expertise and the experience in the intricacies of such observations – e.g., avoiding stray light from (transient) bright sources, scheduling repeat observations to minimize roll angle changes, optimal background subtraction, and source identification. Legacy survey data have no exclusive use period, and are executed by the NuSTAR science team as a service to the community.  Importantly, while some Legacy programs are expected to be fully executed, other programs provide lists of filler/snapshot targets, observed as they fit within the schedule and with no expectation that the entire sample is observed.

Legacy Survey Manifest

Survey Number of
Targets
Total Exposure
(ks)

Extragalactic
XMMLSS 6 300
XBootes 6 300
SDSS Stripe 82 21 1050
Dual AGN 8 160
Seyfert type-1 AGN 6 300
Swift-BAT AGN 6 / month 20 each
NuLANDS 29 990
EHT coordination 6 180
Obscured Seyfert AGN 9 270

Galactic and Nearby Galaxies
Swift Galactic plane survey ToO 75 each
Swift SMC transients (S-CUBED) ToO 50 each
Galactic center molecular clouds 2 450
Sgr A* monitoring 1 100
TeV sources 3 250
Unidentified INTEGRAL sources 3 120
Intermediate Polars / WD mass 25 1020

Cosmic X-ray Background

200

Legacy Survey Target list (ASCII file)


The Extragalactic Survey

One of the principal goals of the NuSTAR extragalactic surveys is to constrain the high-energy X-ray luminosity function and trace its evolution as a function of redshift and AGN obscuration. In previous years, we pursued a multi-layer survey strategy, ranging from ultra-deep observations of selected fields (e.g., ECDFS, EGS, and COSMOS) to shallow observations of wider areas identified through serendipitous source detections.

In 2017 and 2018, most of the extragalactic survey observations consist of targeted observations of interesting sources, useful both for studying those sources and for continuation of the serendipitous program.

1)   Deeper exposures around sources discovered in three sky surveys, XMMLSS, XBootes, and SDSS stripe 82.   50 ks exposures for each position are planned for 2017-2018 (Total 1650 ks), observed on a best-effort basis.

ObsID Name J2000 (deg)
RA Dec
60364001 XMMLSS_001   (1) 34.592333 -5.103950
60364002 XMMLSS_002 35.067750 -4.078042
60364003 XMMLSS_003 34.912833 -5.192706
60364004 XMMLSS_004 35.741583 -4.311372
60364005 XMMLSS_005   (1) 34.454208 -5.385211
60364006 XMMLSS_006 36.457375 -4.006881
60365001 XBootes_001  * 218.934000 35.076178
60365002 XBootes_002 216.189500 33.244019
60365003 XBootes_003 216.348750 35.473378
60365004 XBootes_004 217.551875 33.244361
60365005 XBootes_005  * 217.841083 34.679581
60365006 XBootes_006 217.448583 35.574303
60366001 S82X_001  (2) 43.800917 -0.183547
60366002 S82X_002  * 352.614000 -0.683503
60366003 S82X_003 351.926917 -0.754672
60366004 S82X_004 334.374542 0.818278
60366005 S82X_005 25.624042 -0.598903
60366006 S82X_006 20.000708 -0.371197
60366007 S82X_007 19.128708 0.451014
60366008 S82X_008 18.387708 0.496672
60366009 S82X_009 18.157958 0.086319
60366010 S82X_010 16.595375 -0.355475
60366011 S82X_011 16.528833 0.340319
60366012 S82X_012 16.153333 -0.297100
60366013 S82X_013 13.859375 0.605947
60366014 S82X_014  * 46.175292 -1.053886
60366015 S82X_015  * 54.075375 0.542350
60366016 S82X_016 24.925583 -0.105264
60366017 S82X_017 20.922750 0.743306
60366018 S82X_018 13.870125 0.581256
60366019 S82X_019 352.343625 -0.928497
60366020 S82X_020 353.071958 0.277431
60366021 S82X_021 353.071833 0.278039
* Observation Completed  
(1) Observation postponed, overlap with UDS fields  
(2) Observation postponed. May be observed in NuSTAR GO cycle-3 (proposal 03040).
 
2)  Dual Swift-BAT detected AGN coordinated with XMM-Newton cycle-16 proposal 080220 (PI Koss) (total 140 ks).
 
ObsID Name J2000 (deg) Exposure
RA Dec (ks)
60363001 6dFJ1254564m265702 193.73480000 -26.95050000 20  *
60363002 AM0224m283 36.60810000 -28.35030000 20  *
60363003 2MASXJ02420381p0510061 40.51580000 5.16840000 20  *
60363004 IRAS05589p2828 90.5446 28.4717 20
60363005 1RXSJ213445d2m272551 323.6875 -27.430872 20  *
60363006 Mrk248 198.821937 44.407105 20
60363008 UGC_06081 165.074965 10.049089 20
* Observation Completed

 

3)  Deeper exposures of Swift-BAT detected Seyfert type-1 AGN   (total 350 ks)

 
ObsID Name J2000 (deg) Exposure
RA Dec (ks)
60376001 2MASXJ19301380p3410495 292.557500 34.180500 50
60376002 Mrk463 209.011749 18.371469 50
60376003 1RXSJ034704d9m302409 56.772099 -30.3978 50
60376004 SDSSJ104326d47p110524d2 160.860300 11.090100 50
60376005 Mrk1393 227.224800 -0.197000 50
60376006 3C309d1 224.781600 71.672200 50
60376007 UGC06728 176.316800 79.681500 50
* Observation Completed

 

4)  Swift-BAT detected AGN (20 ks each)

Observations of extragalactic sources taken from the Swift BAT hard X-ray survey will continue in 2017-2018. Each target will be observed for 20 ks by NuSTAR and 7 ks by Swift-XRT. On average 6 sources are observed each month. Previously the 70-month Swift BAT catalog was used for NuSTAR targeting.  In 2017, the sample was increased to include new sources detected in the 105-month survey.

 

5)  NuLANDSRepresentative IRAS-selected AGN sample (total 990 ks)

The distribution of obscuring column densities is a key observational boundary condition for models of AGN evolution and the cosmic X-ray background. The NuSTAR Local AGN N_H Distribution Survey (NuLANDS) will observe a representative sample of 30 IRAS-selected AGN hosts at z<~0.04 to study their gas column densities, and to understand the AGN-galaxy connection.

Each target will also be contemporaneously observed by Swift to obtain 7 ks XRT exposures.

ObsID Name J2000 (deg) Exposure
RA Dec (ks)
60360002 NGC 0449 19.0300485 33.0893489 30
60360003 IC 4995 304.995765 -52.621908 30
60360004 UGC 01214 25.990757 2.349857 30
60360005 2MASX J01500266-0725482 27.5112236 -7.4301471 30
60360006 Mrk 1239 148.0795705 -1.6120791 20
60360007 KUG 0312+013 48.7722605 1.5083828 30
60360008 SDSS J152132.21+391206.9 230.3874232 39.2007671 20
60360009 FAIRALL 0265 104.1241396 -65.5604616 20
60360010 MCG-02-08-039 45.1276199 -11.4158391 30
60361011 2MASXJ 15504152-0353175 237.6729079 -3.8883412 40
60361012 CGCG 498-038 358.9343387 30.2123336 40
60361013 UGC 10120 239.7901018 35.0298614 25
60361014 IC 1198 242.151567 12.3310191 25 *
60361015 MRK 0315 346.0109554 22.6242896 25
60361016 KUG 1021+675 156.304361 67.2971854 40
60361017 ESO 344-G016 333.6750623 -38.8063487 25 *
60361018 KUG 0135-131 24.5224744 -12.8695399 40
60361019 CGCG 004-040 127.5600721 -2.8805107 40
60361020 FGC 0061 8.6812072 -0.0407954 40
60361021 SBS 1426+573 217.0749075 57.1718086 40
60361022 2MASX J03241196-5750116 51.0498478 -57.8367233 40
60361023 UGC 09944 233.9486961 73.450724 30 *
60362024 CGCG 166-047 235.9888601 28.5239359 40 #
60362025 2MASX J21391374-2646315 324.8071404 -26.7754607 40 # *
60362026 2MASX J03381036+0114178 54.5432269 1.238402 40 #
60362027 2MASX J02560264-1629159 44.0110223 -16.4876579 40 #
60362028 CGCG 077-080 230.2218089 8.3968659 40 #
60362029 ESO 018-G009 126.0329349 -77.7825942 30 #
60362030 IRAS 03362-1641 54.6398049 -16.5384568 40 #
* Observation Completed
# Will be coordinated with XMM-Newton cycle-16 priority C observations
(proposal 080515, PI Boorman)
 

6)  Event Horizon Telescope (EHT) multiwavelength campaigns    (total 180 ks)

NuSTAR will join the multiwavelength coordinated observation campaign with the EHT that will probe the innermost regions of accretion flow and jet bases from six nearby active galactic nuclei including the center of the Milky Way. This will offer a unique opportunity to cross-correlate the hard X-ray variability and spectral analysis with structural changes observed by the EHT. Observations are planned for April 2018.
 
ObsID Name J2000 (deg) Exposure
RA Dec (ks)
60466001 Sgr A* 266.416837 -29.007811 55
60466002 M87 187.705830 12.391110 45
60466003 OJ287 133.70365 20.1085 20
60466004 PKS B1055+018 164.623355 1.566340 20
60466005 Cen A 201.36506333 -43.0191125 20
60466006 Mrk 501 253.46758334 39.7601667 20
# Observation Completed
 

7)   The NuSTAR Obscured Seyferts Survey  (total 270 ks)

NuSTAR is uniquely able to detect faint AGN out to high energy.  This capability is essential to accurately measuring obscuring columns, Eddington fractions, and other fundamental properties, especially when columns approach the Compton-thick regime and Eddington fractions are low. This survey finishes NuSTAR observations of a complete, optically selected, volume-limited survey of Seyfert AGN. Each of the sources listed below will be observed for 30 ks with NuSTAR, and 7 ks with Swift. Additional details of the survey can be found at   https://lsa.umich.edu/astro/people/core-faculty/jonmm.html

 

ObsID Name J2000 (deg) Exposure
RA Dec (ks)
60465001 Mrk 334 0.7901 21.96025 30
60465002 UM 146 28.841738 6.611703 30
60465003 NGC 3362 161.215515 6.596915 30
60465004 UGC 6100 165.391679 45.653786 30
60465005 NGC 5256 204.5742 48.2781 30
60465006 NGC 5283 205.273896 67.67215 30
60465007 Mrk 461 206.824125 34.148864 30
60465008 Mrk 471 215.730775 32.850572 30
60465009 NGC 5929 231.525658 41.670667 30
* Observation Completed

 


The Galactic and Nearby Galaxies Survey

NuSTAR is allowing us to probe more deeply into the Galaxy than ever before. The goals of these surveys are to expose the hidden Milky Way and reveal the wide range of astrophysics that creates high-energy emission. NuSTAR studies of flares from Sgr A* probing the physical conditions in the immediate vicinity of the nearest supermassive black hole. By studying high-mass X-ray binaries (HMXB) in a range of environments, we can learn about their formation soon after a supernova event and determine the fraction of HMXBs with black holes. The latter is important for answering questions about HMXB evolution, such as how many neutron star/black hole binaries exist, which has important implications for future gravity wave experiments. In addition to point source studies, NuSTAR is also investigating diffuse emission toward the Galactic Center, including the Galactic ridge emission and the time variation of the reflected emission from dense molecular clouds that probe the accretion history of Sgr A*. The coordinates and characteristics of any transient discovered will immediately be broadcast to the community via electronic circulars such as the Astronomer’s Telegram.

There are seven survey programs approved for observations in 2017 and 2018:

1) Swift Galactic Plane Survey Key Project  -  NuSTAR observations of sources identified during the Swift Galactic plane survey (Multiple targets, 500 ks total)

ObsID

Name

J2000 (deg)

Exposure

RA

Dec

(ks)

30360001

Swift J1843.5-0343

280.89481

-3.71571

75  *

* Observation Completed
 
2) SMC transients  -   followup of targets detected during the Swift SMC Survey (S-CUBED) (Multiple targets, 200 ks total)
 

ObsID

Name

J2000 (deg)

Exposure

RA

Dec

(ks)

30361001

SXP_59d0

13.7340833

-72.4466389

50  *

* Observation Completed
 
3) Galactic Center Molecular Clouds (450 ks)
 

ObsID

Name

J2000 (deg)

Exposure

RA

Dec

(ks)

40113001

Sgr A Molecular Cloud

266.4747

-28.9013

2 x 150 *

40401001

Sgr B2

266.8350

-28.385278

150 #

* The first of the two observations was performed in 2016 October
# Coordinated with XMM-Newton cycle-16 proposal 080241 (PI Zhang)

 

4) Sgr A* monitoring (100 ks)

Chandra and Spitzer for two 24 hour duration observations in the summer of 2018.

 

5) TeV gamma-ray source survey (250 ks)

ObsID

Name

J2000 (deg)

Exposure

RA

Dec

(ks)

30362001

HESS J0632+057

98.240

5.810

2 x 50 #

30362002

2HWC J1928+178

292.178333

17.774167

100  *

30362003

DA 495

298.070

29.430

50  *

* Observation completed
# Coordianted with VERITAS in Nov-Dec 2017
 

6) Unidentified INTEGRAL sources (120 ks) Coordinated with observations in Chandra cycle-19 proposal 19400256 (5 ks ACIS-S, PI Tomsick).

NuSTAR+Chandra observations aim to determine the nature of >20 keV INTEGRAL sources at low Galactic latitudes. Based on Swift/XRT observations, these three sources are known to have extremely hard spectra (power-law Gamma values between -0.1 and 0.4) and so are good candidates to be HMXBs or CV/IPs. The NuSTAR+Chandra data will be used to confirm that these targets belong to one of these classes. This Legacy program will improve the completeness of classified hard X-ray sources in the Galactic plane, providing a constraint on the low luminosity end of the HMXB population.

 

ObsID

Name

J2000 (deg)

Exposure

RA

Dec

(ks)

30401002

IGR J19498+2534

297.47875

25.5641944

45

30401003

IGR J20063+3641

301.5950

36.694306

35

30401004

IGR J17528-2022

268.204583

-20.404111

40

* Observation completed
 

7) Survey of Intermediate Polars    (total 1020 ks)

Intermediate Polars (IP) are binary systems in which matter from a main sequence companion is accreted along magnetic field lines onto the poles of a magnetic white dwarf (WD). This systematic survey of 25 IPs selected from the Swift-BAT 70 month catalog aims to measure the masses of the WDs and constrain the mass distribution of these magnetic cataclysmic variable systems.

ObsID Name J2000 (deg) Exposure
RA Dec (ks)
30460001 1RXS J21334.1+510725 323.43179 51.12353 25
30460002 FO Aqr 334.48075 -08.35108 25
30460003 V2400 Oph 258.15175 -24.24581 25
30460004 V1432 Aql 295.04758 -10.42383 25
30460005 IGR J17195-4100 259.89833 -41.01514 25
30460006 XY Ari 44.034104 19.442811 30
30460007 V405 Aur 89.49708 53.89581 30
30460008 AO Psc 343.82496 -03.17778 35
30460009 PQ Gem 117.822179 14.739972 35
30460010 BY Cam 85.70333 60.85872 35
30460011 EI Uma 129.59167 48.6339 35
30460012 V667 Pup 113.15683 -13.51925 40
30460013 IGR J15094-6649 227.35837 -66.82314 40
30460014 IGR J16500-3307 252.481842 -33.117250 40
30460015 V1062 Tau 75.61450 24.75644 40
30460016 IGR J16547-1916 253.682317 -19.275228 45
30460017 IGR J04571+4527 74.279133 45.463447 45
30460018 BG CMi 112.87088 09.93975 45
30460019 V515 And 13.8329 46.2158 50
30460020 1RXS J052523.2+241331 81.34479 24.22597 55
30460021 RX J2015.6+3711 303.90400 37.18978 55
30460022 YY Dra 175.8958 71.7033 55
30460023 V2069 Cyg 320.93675 42.30047 60
30460024 IGR J14536-5522 223.42108 -55.36075 60
30460025 IGR J08390-4833 129.70462 -48.52356 60
* Observation Completed
 

Cosmic X-ray Background (CXB) (200 ks)

The cosmic X-ray background (CXB) was discovered over 50 years ago, and represents an important integral of the total accretion power of supermassive black holes. However, despite many attempts to measure its spectrum, the normalization of the spectrum at ~3-20keV has considerable uncertainty. In this legacy survey we plan to use the Moon as a shutter, enabling a clear and unambiguous measurement of the CXB to be made with NuSTAR. During the observation we will track the Moon while it oscillates, due to parallax, over 4 degrees of sky. An exposure of 200ks is sufficient to achieve our goal of measuring the normalization and spectral shape of the CXB.


Get Involved!

Interested in providing feedback about the Legacy Surveys? We are now activiely soliciting input from the community. Please give us your thoughts!