We present a study of the narrow Fe K$\alpha$ line in seven bright, nearby AGN that have been observed extensively with Chandra High Energy Transmission Grating (HETG). The HETG data reveal wider first order spectrum than second and third spectra, which we interpret as result spatially extended emission. utilize these differences widths multi-order spectra to determine spatial extent intrinsic ...

The ground-based gravitational wave (GW) observatories discover a population of merging stellar binary black holes (BBHs), which are promising targets for multiband observations by the low-, middle-, and high-frequency GW detectors. In this paper, we investigate detections BBHs demonstrate advantages such in improving localization parameter estimates sources. We generate mock samples considerin...

We present new radio and optical data, including very long baseline interferometry, as well archival data analysis, for the luminous decades-long transient FIRST J141918.9+394036. The reveal a synchrotron self-absorption peak around 0.3 GHz radius of 1.3 mas (0.5 pc) 26 years post-discovery, indicating blastwave energy $\sim5 \times 10^{50}$ erg. spectrum shows broad [OIII]$\lambda$4959,5007 em...

The excitation of $f$-mode in a neutron star member coalescing binaries accelerates the merger course, and thereby introduces phase shift gravitational waveform. Emphasising on tidal by aligned, rotating stars, we provide an accurate, yet economical, method to generate $f$-mode-involved, pre-merger waveforms using realistic spin-modulated frequencies for some viable equations state. We find slo...

We introduce COMAP-EoR, the next generation of Carbon Monoxide Mapping Array Project aimed at extending CO intensity mapping to Epoch Reionization. COMAP-EoR supplements existing 30 GHz COMAP Pathfinder with two additional instruments and a new 16 receiver. This combination frequencies will be able simultaneously map CO(1--0) CO(2--1) reionization redshifts ($z\sim5-8$) in addition providing si...

SDSS J134244.4+053056 is a tidal disruption event candidate with strong temporal coronal line emitters and long fading, mid-infrared dust echo. We present detailed analyses of X-ray emission from Swift/XRT observation in 2009 the most recent XMM-Newton/pn 2020. The two spectra can be modeled hard soft components. While no significant variability detected component above 2 keV between these obse...

We report the time-resolved spectral analysis of a bright near-infrared and moderate X-ray flare Sgr A*. obtained light curves in $M$-, $K$-, $H$-bands mid- $2-8~\mathrm{keV}$ $2-70~\mathrm{keV}$ bands X-ray. The observed slope band is $\nu L_\nu\propto \nu^{0.5\pm0.2}$; L_\nu \propto \nu^{-0.7\pm0.5}$. tested synchrotron self-Compton (SSC) scenarios. brightness faintness, together with slopes,...

We study the evolution of binary black hole (BBH) mass distribution across cosmic time. The second gravitational-wave transient catalog (GWTC-2) from LIGO/Virgo contains BBH events out to redshifts $z \sim 1$, with component masses in range $\sim5$--$80\,M_\odot$. In this catalog, biggest holes, $m_1 \gtrsim 45\,M_\odot$, are only found at highest redshifts, 0.4$. ask whether absence high-mass ...

The stellar initial mass function (IMF) is fundamental for many areas of astrophysics, but its origin remains poorly understood. It may be inherited from the core (CMF) or arise as a result more chaotic, competitive accretion. Dense, gravitationally bound cores are seen in molecular clouds and some observations have suggested that CMF similar shape to IMF, though translated higher masses by fac...

The nebular recombination line H$\alpha$ is widely used as a star-formation rate (SFR) indicator in the local and high-redshift Universe. We present detailed radiative transfer study of high-resolution isolated Milky-Way Large Magellanic Cloud simulations that include transfer, non-equilibrium thermochemistry, dust evolution. focus on spatial morphology temporal variability emission, its connec...