Nearly every massive galaxy harbors a supermassive black hole (SMBH) in its nucleus. SMBH masses are millions to billions $M_{\odot}$, and they correlate with properties of spheroids their host galaxies. While the growth channels, mergers gas accretion, well established, origin remains uncertain: could have either emerged from "seeds" ($10^5-10^6 M_{\odot}$) formed by direct collapse clouds early Universe or smaller ($100 holes, end-products first stars. The latter channel would leave behind...

Ultra-diffuse galaxies (UDGs) are spatially extended, low surface brightness stellar systems with regular elliptical-like morphology found in a wide range of environments. Studies the internal dynamics and dark matter content UDGs that would elucidate their formation evolution have been hampered by brightnesses. Here we present resolved velocity profiles, dispersions, ages metallicities for 9 Coma cluster. We use intermediate-resolution spectra obtained Binospec, MMT's new high-throughput...

Abstract We present RCSED, the value-added Reference Catalog of Spectral Energy Distributions galaxies, which contains homogenized spectrophotometric data for 800,299 low- and intermediate-redshift galaxies ( <?CDATA $0.007\lt z\lt 0.6$?> ) selected from Sloan Digital Sky Survey spectroscopic sample. Accessible Virtual Observatory (VO) complemented with detailed information on galaxy properties obtained state-of-the-art analysis, RCSED enables direct studies formation evolution over last 5...

Low-mass active galactic nuclei (AGNs) can provide important constraints on the formation and evolution of supermassive black holes (SMBHs), a central challenge in modern cosmology. To date only small samples intermediate-mass (IMBHs, $M_{BH}<10^5M_{\odot}$) 'lesser' (LSMBHs, $M_{BH}<10^6M_{\odot}$) have been identified. Our present study NGC 3259 at D=27 Mpc with Binospec integral field unit spectrograph complemented Keck Echelle Spectrograph Imager observations demonstrates need for power...

The next generation large ground-based telescopes like the Vera Rubin Telescope Legacy Survey of Space and Time (LSST) space missions Euclid Nancy Roman will deliver wide area imaging surveys at unprecedented depth. In particular, LSST provide galaxy cluster catalogs up to z∼1 that can be used constrain cosmological models once their selection function is well-understood. Machine learning based detection algorithms applied directly on images circumvent systematics due photometric redshift...

Abstract We report on the intriguing properties of a variable X-ray source projected at outskirts elliptical galaxy NGC 6099 ( d ≈ 139 Mpc). If truly located near 6099, this is hyperluminous that reached an luminosity L X few times 10 42 erg s −1 in 2012 February (XMM-Newton data), about 50–100 brighter than 2009 May (Chandra) and 2023 August (XMM-Newton). The spectrum was soft all three epochs, with thermal component kT 0.2 keV power-law photon index &gt;3. Such make it strong candidate for...

ABSTRACT Giant low surface brightness galaxies (gLSBGs) with dynamically cold stellar discs reaching the radius of 130 kpc challenge currently considered galaxy formation mechanisms. We analyse new deep long-slit optical spectroscopic observations, archival images, and published Hi data for a sample seven gLSBGs, which we performed mass modelling estimated parameters dark matter haloes assuming Burkert density profile. Our is not homogeneous by morphology, populations, total mass, however,...

Abstract We present reprocessed flux-calibrated spectra of 406 stars from the UVES-POP stellar library in wavelength range 320–1025 nm, which can be used for population synthesis. The are provided two versions having spectral resolving power R = 20,000 and 80,000. Raw ESO data archive were re-reduced using latest version UVES reduction pipeline with some additional algorithms that we developed. most significant improvements comparison original release (i) an updated echelle order merging,...

(Abridged) Galaxy clusters are a powerful probe of cosmological models. Next generation large-scale optical and infrared surveys will reach unprecedented depths over large areas require highly complete pure cluster catalogs, with well defined selection function. We have developed new detection algorithm YOLO-CL, which is modified version the state-of-the-art object deep convolutional network YOLO, optimized for galaxy clusters. trained YOLO-CL on color images redMaPPer detections in SDSS....

Galaxy clusters are powerful probes for cosmological models. Next-generation, large-scale optical and infrared surveys poised to reach unprecedented depths and, thus, they require highly complete pure cluster catalogs, with a well-defined selection function. We have developed new detection algorithm named YOLO CLuster ( YOLO–CL ), which is modified version of the state-of-the-art object deep convolutional network You only look once ) that has been optimized galaxy clusters. trained on...

ABSTRACT Rare giant low surface brightness galaxies (gLSBGs) act as a stress test for the current galaxy formation paradigm. To answer question ‘How rare are they?’, we estimate their volume density in local Universe. A visual inspection of 120 deg2 covered by deep Subaru Hyper Suprime-Cam data was performed independently four team members. We detected 42 disky systems (30 them isolated) at z ≤ 0.1 with either g-band 27.7 mag arcsec−2 isophotal radius or disc scale lengths 4h ≥ 50 kpc, 37...

The low-mass low-surface brightness (LSB) disc galaxy Arakelian 18 (Ark 18) resides in the Eridanus void and because of its isolation represents an ideal case to study formation evolution mechanisms such a type. Its complex structure consists extended blue LSB bright central elliptically-shaped part hosting massive off-centered star-forming clump. We present in-depth Ark based on observations with SCORPIO-2 long-slit spectrograph scanning Fabry-Perot interferometer at Russian 6-m telescope...

Abstract To understand the origin of extended disks low-surface brightness (LSB) galaxies, we studied in detail four such systems with large seen edge on. Two them are edge-on giant LSB galaxies (gLSBGs) recently identified by our team. The orientation these boosts their surface brightnesses that provided an opportunity to characterize stellar populations spectroscopically and yielded first measurements for gLSBGs. We collected deep images one galaxy using 1.4 m Milanković Telescope, which...

Abstract The outermost edges of some supernova remnants are marked by filaments pure Balmer line emission produced nonradiative shock fronts. H α profiles these provide the speed and electron–proton temperature ratio in shock. We have used Hectochelle multiobject spectrograph on MMT telescope to observe nine positions along eastern Cygnus Loop, thereby extending studies Medina et al. lower speeds. complement spectra with images from 1993 2020 measure proper motions further constrain...

Low-mass early-type galaxies, including dwarf spheroidals (dSph) and brighter ellipticals (dE), dominate the galaxy population in groups clusters. Recently, an additional of more extended ultradiffuse galaxies (UDGs) has been identified, sparking a discussion on potential morphological evolutionary connections between three classifications. Here, we present first measurements spatially resolved stellar kinematics from deep integrated-light spectra KDG 64 (UGC 5442), large dSph M 81 group....

Over the past 2 decades, wide-field photometric surveys in optical and infrared domains reached a nearly all-sky coverage thanks to numerous observational facilities operating both hemispheres. However, subtle differences among exact realizations of Johnson SDSS systems require one convert measurements into same system prior analysis composite datasets originating from multiple surveys. It turns out that published transformations lead substantial biases when applied integrated photometry...

Pixel-space full spectrum fitting exploiting non-linear $\chi^2$ minimization became a \emph{de facto} standard way of deriving internal kinematics from absorption line spectra galaxies and star clusters. However, reliable estimation uncertainties for kinematic parameters remains challenge is usually addressed by running computationally expensive Monte-Carlo simulations. Here we derive simple formulae the radial velocity dispersion based solely on shape template used in procedure...

The origin of supermassive black holes (SMBH) in galaxy centers still remains uncertain. There are two possible ways oftheir formation — from massive (10 5 − 10 6 M ⊙ ) and low-mass (100 BH nuclei. latter scenario should leave behinda large number intermediate mass (IMBH, 2 ). largest published sample bona-fide IMBH-powered AGN contains objects confirmed X-ray. Here we present a new 15 IMBHs, obtainedby confirming the optically selected IMBH candidates by presence radiation galactic nucleus...

Ultra-diffuse galaxies (UDGs) are spatially extended, low surface brightness stellar systems with regular elliptical-like morphology found in large numbers galaxy clusters and groups. Studies of the internal dynamics dark matter content UDGs have been hampered by their brightnesses. We identified a sample low-mass early-type post-starburst galaxies, `future UDGs' Coma cluster still populated young stars, which will passively evolve into next 5$-$10 Gyr. collected deep observations for using...

To understand the origin of extended disks low-surface brightness (LSB) galaxies, we studied in detail 4 such systems with large seen edge-on. Two them are edge-on giant LSB galaxies (gLSBGs) recently identified by our team. The orientation these boosts their surface brightnesses that provided an opportunity to characterize stellar populations spectroscopically and yielded first measurements for gLSBGs. We collected deep images one galaxy using 1.4-m Milankovi\'c Telescope which combined...

LSST will provide galaxy cluster catalogs up to z$\sim$1 that can be used constrain cosmological models once their selection function is well-understood. We have applied the deep convolutional network YOLO for CLuster detection (YOLO-CL) simulations from Dark Energy Science Collaboration Data Challenge 2 (DC2), and characterized YOLO-CL function. trained validated on images a hybrid sample of (1) clusters observed in Sloan Digital Sky Survey detected with red-sequence Matched-filter...

Galaxy clusters are the largest gravitationally bound structures in Universe and therefore a powerful tool for studying mass assembly at different epochs. At z &gt; 2, they provide unique opportunity to place solid constraints not only on growth of dark matter halo, but also mechanisms galaxy quenching morphological transformation when was younger than 3.3 Gyr. However, currently available sample confirmed 2 remains very limited. We present spectroscopic confirmation cluster CARLA J0950+2743...