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Register a new userSimultaneous Chandra and RXTE Spectroscopy of the Microquasar H~1743-322: Clues to Disk Wind and Jet Formation from a Variable Ionized Outflow
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J. M. Miller
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We observed the bright phase of the 2003 outburst of the Galactic black hole candidate H 1743-322 in X-rays simultaneously with Chandra and RXTE on four occasions. The Chandra/HETGS spectra reveal narrow, variable (He-like) Fe XXV and (H-like) Fe XXVI resonance absorption lines. In the first observation, the Fe XXVI line has a FWHM of 1800 +/- 400 km/s and a blue-shift of 700 +/- 200 km/s, suggesting that the highly ionized medium is an outflow. Moreover, the Fe XXV line is observed to vary significantly on a timescale of a few hundred seconds in the first observation, which corresponds to the Keplerian orbital period at approximately 1 E+4 gravitational radii. Our models for the absorption geometry suggest that a combination of geometric effects and changing ionizing flux are required to account for the large changes in line flux observed between observations, and that the absorption likely occurs at a radius less than 1 E+4 radii for a 10 Msun black hole. Viable models for the absorption geometry include cyclic absorption due to an accretion disk structure, absorption in a clumpy outflowing disk wind, or possibly a combination of these two. If the wind in H 1743-322 has unity filling factor, the highest implied mass outflow rate is 20 percent of the Eddington mass accretion rate. This wind may be a hot precursor to the Seyfert-like, outflowing warm absorber geometries recently found in the Galactic black holes GX 339-4 and XTE J1650-500. We discuss these findings in the context of ionized Fe absorption lines found in the spectra of other Galactic sources, and connections to warm absorbers, winds, and jets in other accreting systems.
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X-ray disk winds are detected in spectrally soft, disk-dominated phases of stellar-mass black hole outbursts. In contrast, compact, steady, relativistic jets are detected in spectrally hard states that are dominated by non-thermal X-ray emission. Although these distinctive outflows appear to be almost mutually exclusive, it is possible that a disk wind persists in hard states but cannot be detected via X-ray absorption lines owing to very high ionization. Here, we present an analysis of a deep, 60 ksec Chandra/HETGS observation of the black hole candidate H 1743-322 in the low/hard state. The spectrum shows no evidence of a disk wind, with tight limits, and within the range of ionizing flux levels that were measured in prior Chandra observations wherein a wind was clearly detected. In H 1743-322, at least, disk winds are actually diminished in the low/hard state, and disk winds and jets are likely state-dependent and anti-correlated. These results suggest that although the launching radii of winds and jets may differ by orders of magnitude, they may both be tied to a fundamental property of the inner accretion flow, such as the mass accretion rate and/or the magnetic field topology of the disk. We discuss these results in the context of disk winds and jets in other stellar-mass black holes, and possible launching mechanisms for black hole outflows.
We report on the formation and evolution of two large-scale, synchrotron-emitting jets from the black hole candidate H 1743-322 following its reactivation in 2003. In November 2003 after the end of its 2003 outburst, we noticed, in observations with the Australia Telescope Compact Array, the presence of a new and variable radio source about 4.6 to the East of H 1743-322, that was later found to move away from H 1743-322. In February 2004, we detected a radio source to the West of H 1743-322, symmetrically placed relative to the Eastern jet. In 2004, follow-up X-ray observations with {em Chandra} led to the discovery of X-ray emission associated with the two radio sources. This likely indicates that we are witnessing the interaction of relativistic jets from H 1743-322 with the interstellar medium causing in-situ particle acceleration. The spectral energy distribution of the jets during the decay phase is consistent with a classical synchrotron spectrum of a single electron distribution from radio up to X-rays, implying the production of very high energy ($>$ 10 TeV) particles in those jets. We discuss the jet kinematics, highlighting the presence of a significantly relativistic flow in H 1743-322 almost a year after the ejection event.
Using black body and power-law photon counts of All Sky Monitor (ASM) in Rossi X-ray Timing Explorer (RXTE) satellite it has been established recently by us that there is a significant time lag between the infall timescales of two components in the Two-Component Advective Flow (TCAF) paradigm, where a standard slow moving Keplerian disc is surrounded by a fast moving halo. The time lag is clearly due to the difference in viscosity in the flow components and the size of the Keplerian disc may be considered to be proportional to the arrival time lag. In this paper, using RXTE/ASM (1.5-12 keV) data, we examine eight successive outbursts of the low-mass X-ray binary H 1743-322 since 2003 from a new angle. A dynamic photon index, {Theta} indicates that the size of the Keplerian disc is biggest during the brightest outburst of 2003. The size diminishes thereafter during subsequent weaker outbursts. These results are corroborated when two energy fluxes corresponding to the two flows are cross-correlated with reference to {Theta}. Moreover, {Theta} decides spectral transitions of any outburst. We show from the behaviour of {Theta} alone that the outburst of October 2008 was an anomalous outburst. In fact, each normal outburst was either preceded or followed by an otherwise premature outburst. This makes H 1743-322 an enigmatic source and a subject of further study.
On two occasions, we obtained nearly simultaneous ~ 4 kilosecond snapshot observations of the Galactic black hole and microquasar XTE J1550-564 with Chandra and RXTE near the peak of its May, 2000 outburst. The low-energy sensitivity of Chandra and the resolution of the High Energy Transmission Grating Spectrometer (HETGS), coupled with the broad energy range and large collecting area of RXTE, have allowed us to place constraints on the outburst accretion flow geometry of this source in the ``intermediate X-ray state. The 0.65-25.0 keV continuum spectra are well-described by relatively hot (kT ~ 0.8 keV) accretion disk and hard (Gamma ~ 2.3) coronal power-law components. Broad, relatively strong Fe K-alpha emission line (EW ~170 eV) and smeared absorption edge components consistent with Fe XXV are strongly required in joint spectral fits. The resolution of the Chandra/HETGS reveals that the broad Fe K-alpha emission lines seen clearly in the individual RXTE spectra are not due to an intrinsically narrow line.
We present the detection of type C quasi-periodic oscillation (QPO) along with upper harmonic at respective frequencies of $sim0.6$ Hz and $sim1.2$ Hz in the single AstroSat observation taken during the 2016 outburst of the low-mass black hole X-ray binary H~1743--322. These frequencies are found to be shifted by $sim0.4$ Hz for the QPO and $sim0.8$ Hz for the upper harmonic with respect to that found in the simultaneous textit{XMM-Newton} and textit{NuSTAR} observation taken five days later than the AstroSat observation, indicating a certain geometrical change in the system. However, the centroid frequency of the QPO and the upper harmonic do not change with energy, indicating the energy-independent nature. The decreasing trend in the fractional rms of the QPO with energy is consistent with the previous results for this source in the low/hard state. The value of the photon index ($Gammasim1.67$) also indicates that the source was in the low/hard state during this particular observation. In addition, similar to the textit{XMM-Newton} observations during the same outburst, we find a hard lag of $sim21$ ms in the frequency range of $sim1-5$ Hz. The log-linear trend between the averaged time lag and energy indicates the propagation of fluctuations in the mass accretion rate from outer part of the accretion disk to the inner hot regions.
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