Abstracts of the 17Th HEAD Meeting (Monterey, CA)
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Abstracts of the 17th HEAD Meeting (Monterey, CA) American Astronomical Society March, 2019 100 — Stellar Compact I 100.02 — Understanding the orbital period and ac- cretion torque in the ultra-luminous X-ray pulsar NGC 7793 P13 100.01 — Ultraluminous X-ray Sources in Extra- 1 2 3 galactic Globular Clusters Felix Fuerst ; Dom Walton ; Marianne Heida ; Fiona Harrison3; Didier Barret4; Murray Brightman3; An- drew Fabian2; Matthew Middleton5; Ciro Pinto2; Kristen Dage1; Stephen Zepf1; Mark Peacock1; Arash Virkam Rana6; Frank Tramper1; Natalie Webb4; Peter Bahramian1,2; Arunav Kundu3; Thomas Maccarone4 Kretschmar1 1 Michigan State University (East Lansing, Michigan, United 1 ESA/ESAC (Villanueva de la Canada, Madrid, Spain) States) 2 IoA Cambridge (Cambridge, United Kingdom) 2 ICRAR (Perth, Western Australia, Australia) 3 Caltech (Pasadena, California, United States) 3 Eureka Scientific (Oakland, California, United States) 4 CNRS (Toulouse, France) 4 Texas Tech University (Lubbock, Texas, United States) 5 University of Southampton (Southampton, United Kingdom) 6 Raman Research Institute (Bangalore, India) Ultra-luminous X-ray pulsars (ULPs) are a new class The question whether globular clusters host black of accreting neutron stars, emitting X-rays orders of holes has been of longstanding interest. This interest magnitude above their Eddington limit. Currenlty has grown dramatically with the LIGO detection of only five ULPs are confirmed. Among them, NGC merging black holes, as black hole mergers formed 7793 P13 stands out among as being relatively easily in globular clusters is one of the leading explana- observable and as the only one with a clearly identi- tions for these LIGO sources. Determining whether fied optical companion, a B9I supergiant. This allows black holes are common in globular clusters (GCs) us to study the binary properties in detail and shed has been an observational challenge. One of the most light on the accretion mechanism in this rare source successful ways to identify candidate black holes in type. The pulsations of the neutron star have a pe- globular clusters is to identify globular cluster X-ray riod around 415ms and have been detected in all X- sources with very high luminosities that are much ray observations so far, allowing us to study the long- greater than the Eddington limit for neutron stars. term spin evolution. I will present results from our A number of ultraluminous X-ray sources (ULXs) 2017-2018 XMM-Newton and NuSTAR campaign on have been found within extragalactic globular clus- this source. Through X-ray timing, we follow the ters, and are candidate accreting black holes. We pulse period evolution and we can unambiguously study spectral properties of GC ULXs over a large measure the orbital period to be ∼64d. Together with span of Chandra observations. We find that the glob- the properties of the mass donor, we describe, for the ular cluster ULXs seem to follow one of two distinct first time in a ULP, the ephemeris of the system fully. trends: one group show a strong correlation between The orbital period is consistent with the optical pho- the accretion disk temperature and X-ray luminosity, tometric period, but significantly shorter than the pe- while another group show no change in disk temper- riodicity of the X-ray flux X(P ∼ 66.5d). I will discuss ature with significant variations in X-ray luminos- possible explanations for this difference, like a very ity. We discuss how these observational results im- long super-orbital or a super- hump period. Adding pact our understanding of the nature of these sources new data from the end of 2018 we see that the spin- and compare them to ULXs in star forming regions up of the source has accelerated, likely due to an in- (very different environments than globular clusters) creased accretion torque. I will put these findings where a number have been shown to be NSs. into context with the other known ULPs and galactic 1 sources. 3 Pennsylvania State University (University Park, Pennsylvania, United States) 4 University of Cambridge (Cambridge, United Kingdom) 100.03 — A Comprehensive Chandra Study of the 5 University of Michigan (Ann Arbor, Michigan, United States) Disk Winds in the Black Hole Candidate 4U 1630- 6 Universite de Toulouse (Toulouse, France) 472 7 ESA/ESAC (Madrid, Spain) Nicolas Antonio Trueba1; Jon Miller1; Jelle Kaastra2; 8 University of Southampton (Southampton, United Kingdom) Abderahmen Zoghbi1 1 Department of Astronomy, University of Michigan (Ann Arbor, Swift J1658.2-4242 is a new Galaltic black hole binary Michigan, United States) candidate viewed at high inclination angle discov- 2 SRON Netherlands Institute for Space Research (Utrecht, Nether- ered during its outburst in early 2018. We obtained lands) broadband X-ray obervations by NuSTAR, Swift and XMM-Newton in the hard and intermediate state, on The mechanisms that drive disk winds are a win- the rising phase of the outburst. We observe strong dow into the physical processes that underlie the disk reflection features with NuSTAR in the hard accretion disk itself, as well as feedback within the state, challenaging the truncated disk hypothesis for broader accretion flow. Transient stellar-mass black the low/hard state of black hole binaries. We also holes are an ideal setting in which to explore these perform detailed spectral modeling yielding a high mechanisms since their outbursts span a broad range black hole spin. An aborption feature is found in the in mass accretion rate. We present a detailed spec- Fe K band in the NuSTAR spectra, impling the un- tral analysis of the disk winds found in six Chan- sual presence of a disk wind in the hard state. In dra/HETG observations of black hole candidate 4U the intermediate state, a peculiar event is observed 1630−472, spanning a wide range of luminosities where the X-ray flux significantly decreased in 40s over two distinct spectral states. Two independent with a turn-on of a low-frequency QPO, while being constraints on launching radii were obtained via the accompanied by only minor changes in the shape of ionization parameter formalism and the dynamical the broadband X-ray spectrum. In addition, strong broadening of wind re- emission; thereby enabling relativistc reflection features previously detected in the characterization of the wind geometry without the hard state are absent. We present the unusual the need of assuming a fiducial gas density. All wind phenomena observed in Swift J1658.2-4242 and re- components display evidence of magnetic driving sults from our spectral and timing analyses, and dis- with launching radii too small for winds arising cuss their implications for the dynamical properties purely via thermal driving. The innermost wind of the inner accretion flow around black hole. components (r ∼ 102−3 GM/c2) are the densest and fastest, while the outer components (r ∼ 105 GM/c2) 100.05 — Accretion States and BH Spin in MAXI have low densities and outflow velocities typically J1535-571 with NICER and NuSTAR associated with thermal winds. This picture is con- Joey Neilsen1; James F. Steiner2; Ron Remillard2; sistent with thermal driving becoming efficient at Phil Uttley3; Jeroen Homan4; Liam Jones1; Sara larger radii, and even suggests the possible detec- Motta5; Mickaël Coriat6; Rob Fender5; Stephane tion of a thermal/magnetic ‘hybrid’ wind. Finally, Corbel8; Gabriele Ponti7; Zaven Arzoumanian9; Keith we find wind mass outflow rates that either match or Gendreau9; Renee Ludlam10 exceed the mass accretion rate, supporting the view 1 Department of Physics, Villanova University (Villanova, Pennsyl- that disk winds are an important component of the vania, United States) overall accretion flow. 2 University of Michigan (Ann Arbor, Michigan, United States) 3 MIT (Cambridge, Massachusetts, United States) 100.04 — The New Black Hole Binary Candidate 4 University of Amsterdam (Amsterdam, Netherlands) Swift J1658.2-4242 Observed by NuSTAR, Swift 5 Eureka Scientific (Oakland, California, United States) and XMM-Newton 6 Oxford (Oxford, United Kingdom) 7 IRAP (Toulouse, France) 1 1 2 Yanjun Xu ; Fiona Harrison ; John Tomsick ; Jamie 8 MPE (Garching, Germany) 3 4 5 6 Kennea ; Dom Walton ; Jon Miller ; Didier Barret ; 9 CEA Saclay (Saclay, France) 4 1 7 Andrew Fabian ; Karl Forster ; Felix Fuerst ; Poshak 10 NASA Goddard (Greenbelt, Maryland, United States) Gandhi8; Javier A. García1 1 Caltech (Pasadena, California, United States) After two decades of monitoring stellar mass black 2 SSL/UCB (Berkeley, California, United States) holes in outburst, there are still lingering questions 2 about the geometry of the accretion disk and its evo- an upper limit on the radio flux of the source. Com- lution across state transitions. Does the disk extend bined with the X-ray flux at the time of the radio ob- all the way to the ISCO, or is it truncated at some servations, we can place the source on the radio–X- distance from the black hole? How does this de- ray “fundamental” plane of accretion activity. The pend on accretion rate, luminosity, and X-ray spec- position on the Lr-Lx plane falls significantly below tral shape, and how is it connected to timing proper- what is expected for black holes. This further sup- ties? The recent outburst of MAXI J1535-571, mon- ports the common assumption that the compact ob- itored extensively with NuSTAR and NICER, pro- ject in 4U 1543-624 is a neutron star, although no vides a prime opportunity to address these ques- Type-I X-ray bursts have ever been observed. tions. I will present detailed analysis of the spectral evolution of the source over roughly three months, from its rising hard states through its >5 Crab peak, 101 — AGN I all the way to its soft, disk-dominated state. Apply- ing relativistic reflection models and holding its spin 101.01 — The ongoing transformation of Seyfert constant across the outburst, I track the evolution of galaxy 1ES 1927+654 the inner radius of the disk from state to state.