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We take advantage of a set of molecular cloud simulations to demonstrate a possibility to uncover statistical properties of the gas density and velocity fields using reflected emission of a short (with duration much less than the clouds light-crossing time) X-ray flare. Such situation is relevant for the Central Molecular Zone of our Galaxy where several clouds get illuminated by a $sim110$ yr-old flare from the supermassive black hole Sgr A*. Due to shortness of the flare ($Delta tlesssim1.6$ yrs), only a thin slice ($Delta zlesssim0.5$ pc) of the molecular gas contributes to the X-ray reflection signal at any given moment, and its surface brightness effectively probes the local gas density. This allows reconstructing the density probability distribution function over a broad range of scales with virtually no influence of attenuation, chemo-dynamical biases and projection effects. Such measurement is key to understanding the structure and star-formation potential of the clouds evolving under extreme conditions in the CMZ. For cloud parameters similar to the currently brightest in X-ray reflection molecular complex Sgr A, the sensitivity level of the best available data is sufficient only for marginal distinction between solenoidal and compressive forcing of turbulence. Future-generation X-ray observatories with large effective area and high spectral resolution will dramatically improve on that by minimising systematic uncertainties due to contaminating signals. Furthermore, measurement of the iron fluorescent line centroid with sub-eV accuracy in combination with the data on molecular line emission will allow direct investigation of the gas velocity field.
We suggest a method for probing global properties of clump populations in Giant Molecular Clouds (GMCs) in the case where these act as X-ray reflection nebulae (XRNe), based on the study of the clumpings overall effect on the reflected X-ray signal,
The abundances of gas and dust (solids and complex molecules) in the interstellar medium (ISM) as well as their composition and structures impact practically all of astrophysics. Fundamental processes from star formation to stellar winds to galaxy fo
Long-lasting, very bright multiwavelength flares of blazar jets are a curious phenomenon. The interaction of a large gas cloud with the jet of a blazar may serve as a reservoir of particles entrained by the jet. The size and density structure of the
Extended emission is a mystery in short gamma-ray bursts (SGRBs). By making time resolved spectral analyses of brightest nine events observed by ${it Swift}$ XRT, we obviously classify the early X-ray emission of SGRBs into two types. One is the exte
We present the result of a study of the X-ray emission from the Galactic Centre Molecular Clouds (MC), within 15 arcmin from Sgr A*. We use XMM-Newton data spanning about 8 years. We observe an apparent super-luminal motion of a light front illuminat