NICER observation list: Target ID 464701

Abstract

GRS 1915+105 is a black hole binary known for its unique variability, strong winds, jets, and BH spin. After 20+ years in outburst, NICER detected a huge change in this iconic source: the X-ray flux dropped by 100x! Spectra suggest a large obscuring shroud, but what is this obscuring gas? The 'obscured' state is highly variable, with flares that reveal strong winds and highly-ionized absorption. We propose to study its long-term evolution with 35 weekly exposures of 2.7 ks in Cycle 2. NICER is the only mission capable of frequently monitoring this important new state. We also request 2x25 ks NuSTAR ToOs to constrain scattering and wind photoionziation. These observations will also grow a NICER legacy archive of obscured variability in GRS 1915+105.
Obsid RA DEC l b Start End Exposure Number of modules Status of Processing Date of Processing Public date
4647010101 288.798 10.945 45.36532 -0.21906 59279.2548 59279.3988 594.00000 49 VALIDATED 59283.7 59293
4647010201 288.798 10.945 45.36540 -0.21913 59284.1599 59284.2576 1367.00000 49 VALIDATED 59293.8 59298
4647010301 288.798 10.946 45.36546 -0.21888 59291.4555 59291.5437 2989.00000 52 VALIDATED 59296.0 59305
4647010401 288.798 10.945 45.36542 -0.21934 59296.6859 59296.9551 3977.00000 52 VALIDATED 59300.7 59310
4647010402 288.798 10.945 45.36534 -0.21916 59297.0090 59297.0824 1053.00000 52 VALIDATED 59301.6 59311
4647010501 288.797 10.942 45.36235 -0.22007 59305.1708 59305.3116 0.00000 52 VALIDATED 59314.8 59319
4647010601 288.800 10.945 45.36589 -0.22087 59312.1280 59312.2220 3085.00000 52 VALIDATED 59321.8 59326
4647010701 288.798 10.945 45.36512 -0.21961 59319.1711 59319.2613 3279.00000 52 VALIDATED 59330.9 59333
4647010801 288.798 10.946 45.36586 -0.21922 59326.3949 59326.5391 3573.00000 52 VALIDATED 59336.8 59340
4647010802 288.799 10.945 45.36538 -0.21992 59329.8814 59329.9627 2439.00000 52 VALIDATED 59340.0 59343
4647010803 288.797 10.947 45.36640 -0.21761 59330.0101 59330.0271 976.00000 52 VALIDATED 59340.0 59344
4647010804 288.798 10.947 45.36648 -0.21823 59331.9480 59331.9535 205.00000 52 VALIDATED 59341.9 59345
4647010901 288.798 10.946 45.36590 -0.21875 59332.9875 59332.9979 821.00000 52 VALIDATED 59344.7 59346
4647010902 288.798 10.946 45.36578 -0.21871 59333.1748 59333.3854 2524.00000 52 VALIDATED 59343.7 59347
4647011101 288.799 10.947 45.36704 -0.21960 59349.8377 59349.9806 2563.00000 52 VALIDATED 59359.7 59363
4647011102 288.798 10.945 45.36504 -0.21876 59350.0323 59350.0451 994.00000 52 VALIDATED 59359.7 59364
4647011201 288.798 10.946 45.36568 -0.21909 59354.3073 59354.5808 2290.00000 52 VALIDATED 59367.1 59368
4647011301 288.798 10.945 45.36514 -0.21915 59361.3287 59361.4225 1910.00000 52 VALIDATED 59371.7 59375
4647011401 288.797 10.943 45.36243 -0.21936 59368.6905 59368.7771 3614.00000 52 VALIDATED 59378.7 59382
4647011501 288.798 10.946 45.36570 -0.21920 59375.0848 59375.4156 2359.00000 52 VALIDATED 59384.8 59389
4647011601 288.801 10.944 45.36556 -0.22281 59382.0646 59382.1560 2193.00000 52 VALIDATED 59391.8 59396
4647011701 288.799 10.944 45.36465 -0.22030 59389.6907 59389.7771 3365.00000 52 VALIDATED 59401.9 59403
4647011801 288.798 10.946 45.36589 -0.21898 59396.2703 59396.4738 3036.00000 52 VALIDATED 59407.9 59410
4647011901 288.798 10.946 45.36592 -0.21863 59403.3745 59403.4604 3241.00000 52 VALIDATED 59412.9 59417