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تسجيل مستخدم جديدMulti-wavelength observation of MAXI J1348-630 during the recent outburst using ALMA/Chandra/NuSTAR
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We studied the multi-wavelength timing and spectral properties of the high mass X-ray binary MAXI J1348$-$630 during two successive outbursts of April and June 2019 using ALMA, Swift, Chandra, NuSTAR and NICER. The position of the source was measured by Chandra (RA=13h48m12.878s, Dec=$-$63$^{circ}$1628.85) with enhanced accuracy. The soft X-ray spectrum (1$-$6 keV) was intensively studied using Chandra/HETG from which multiple absorption-features corresponding to Fe XXII, Fe XXIII, Si XII, Cl XVI, S XV, Ar XVIII lines and the emission features corresponding to Fe XXI, Fe XXIII, Ar XVI lines were detected. We studied the first broadband spectrum for this black hole that included fluxes in radio, optical, ultraviolet and X-ray energy bands using data from ALMA (band 3, 4, 6 and 7; 89.56$-$351.44 GHz) and swift (UVOT and XRT). The broadband study suggested that the source was accompanied by strong blackbody radiation from the disk associated with weak synchrotron emission from the compact jets. The X-ray spectrum was also studied using NuSTAR in the range of 3$-$78 keV. We studied the evolution of spectral parameters using NuSTAR observations (from MJD 58655 to MJD 58672) when the source remained in the canonical hard state during the outburst of June 2019. We detected two type-C QPOs during the outburst of June 2019 with decreasing centroid frequencies from 0.82 Hz to 0.67 Hz and decreasing RMS amplitude from 7.6 per cent to 2.1 per cent. The hardness ratio showed significant variation during the outburst of April 2019 but remained almost constant during the outburst of June 2019. The spectral evolution in the hardness intensity diagram was studied during the outbursts.
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We present the broadband spectral analysis of all the six hard, intermediate and soft state NuSTAR observations of the recently discovered transient black hole X-ray binary MAXI J1348-630 during its first outburst in 2019. We first model the data wit
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We present the radio and X-ray monitoring campaign of the 2019/2020 outburst of MAXI J1348-630, a new black hole X-ray binary (XRB) discovered in 2019 January. We observed MAXI J1348-630 for $sim$14 months in the radio band with MeerKAT and the Austr
alia Telescope Compact Array (ATCA), and in the X-rays with MAXI and Swift/XRT. Throughout the outburst we detected and tracked the evolution of the compact and transient jets. Following the main outburst, the system underwent at least 4 hard-state-only re-flares, during which compact jets were again detected. For the major outburst, we observed the rise, quenching, and re-activation of the compact jets, as well as two single-sided discrete ejecta, launched $sim$2 months apart and travelling away from the black hole. These ejecta displayed the highest proper motion ($gtrsim$100 mas day$^{-1}$) ever measured for an accreting black hole binary. From the jet motion, we constrain the ejecta inclination and speed to be $leq$46$^{circ}$ and $geq$0.69 $c$, and the opening angle and transverse expansion speed of the first component to be $leq$6$^{circ}$ and $leq$0.05 $c$. We also infer that the first ejection happened at the hard-to-soft state transition, before a strong radio flare, while the second ejection was launched during a short excursion from the soft to the intermediate state. After traveling with constant speed, the first component underwent a strong deceleration, which was covered with unprecedented detail and suggested that MAXI J1348-630 could be located inside a low-density cavity in the interstellar medium, as already proposed for XTE J1550-564 and H1743-322.
The fast variability observed in the X-ray emission from black-hole binaries has a very complex phenomenology, but offers the possibility to investigate directly the properties of the inner accretion flow. In particular, type-B oscillations in the 2-
8 Hz range, observed in the Soft-Intermediate state, have been associated to the emission from a relativistic jet. We present the results of the timing and spectral analysis of a set of observations of the bright transient MAXI J1348-630 made with the NICER telescope. The observations are in the brightest part of the outburst and all feature a strong type-B QPO at ~4.5 Hz. We compute the energy dependence of the fractional rms and the phase lags at the QPO frequency, obtaining high signal-to-noise data and sampling for the first time at energies below 2 keV. The fractional rms decreases from more than 10% at 9 keV to 0.6% at 1.5 keV, and is constant below that energy. Taking the 2-3 keV band as reference, photons at all energies show a hard lag, increasing with the distance from the reference band. The behaviour below 2 keV has never been observed before, due to the higher energy bandpass of previous timing instruments. The energy spectrum can be fitted with a standard model for this state, consisting of a thin disc component and a harder power law, plus an emission line between 6 and 7 keV. We discuss the results, concentrating on the phase lags, and show that they can be interpreted within a Comptonization model.
MAXI J1813-095 is an X-ray transient discovered during an outburst in 2018. We report on X-ray and optical observations obtained during this event, which indicate that the source is a new low-mass X-ray binary. The outburst lasted ~70 d and peaked at
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Black hole low mass X-ray binaries in their hard spectral state are found to display two different correlations between the radio emission from the compact jets and the X-ray emission from the inner accretion flow. Here, we present a large data set o
f quasi-simultaneous radio and X-ray observations of the recently discovered accreting black hole MAXI J1348-630 during its 2019/2020 outburst. Our results span almost six orders of magnitude in X-ray luminosity, allowing us to probe the accretion-ejection coupling from the brightest to the faintest phases of the outburst. We find that MAXI J1348-630 belongs to the growing population of outliers at the highest observed luminosities. Interestingly, MAXI J1348-630 deviates from the outlier track at $L_{rm X} lesssim 7 times 10^{35} (D / 2.2 {rm kpc})^2$ erg s$^{-1}$ and ultimately rejoins the standard track at $L_{rm X} simeq 10^{33} (D / 2.2 {rm kpc})^2$ erg s$^{-1}$, displaying a hybrid radio/X-ray correlation, observed only in a handful of sources. However, for MAXI J1348-630 these transitions happen at luminosities much lower than what observed for similar sources (at least an order of magnitude). We discuss the behaviour of MAXI J1348-630 in light of the currently proposed scenarios and we highlight the importance of future deep monitorings of hybrid correlation sources, especially close to the transitions and in the low luminosity regime.
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