ASTRONOMICAL PLATES SPECTRA EXTRACTION OBJECTIVES AND POSSIBLE SOLUTIONS IMPLEMENTED ON DIGITIZED FIRST BYURAKAN SURVEY (DFBS) IMAGES

Astronomical images extraction process with usage of the Source Extractor (SE) tool is presented in this paper. The specificity of DFBS plates is that objects are presented in low-dispersion spectral form. It does not allow extraction tools to detect the objects exact coordinates and there is need of coordinates' correction. Apart thi

Cloud-Based Machine Learning Service for Astronomical Sub-Object Classification: Case Study On the First Byurakan Survey Spectra

The classification of astronomical objects in the Digitized First Byurakan Survey (DFBS), comprising low-dispersion spectra for approximately twenty million objects, presents challenges regarding performance and computational resources. However, considering the distinct spectral characteristics within subgroups, sub-object classification becomes crucial for a more detailed understanding of the dataset. The article addresses these challenges by proposing a comprehensive cloud-based service for classifying objects into spectral classes and subtypes, with a focus on carbon stars, white dwarfs / subdwarfs, and Markarian (UV-excess) galaxies, which are the primary objects in DFBS. By leveraging the power of cloud computing, it effectively handles the computational requirements associated with analyzing the extensive DFBS dataset. The service employs advanced machine learning algorithms trained on labeled data to classify objects into their respective spectral types and subtypes. The service can be accessed and utilized through a user-friendly interface, making it accessible to a wide range of users in the astronomical community

Verification of Photometric Parallaxes with Gaia DR2 Data

Results of comparison of Gaia DR2 parallaxes with data derived from a combined analysis of 2MASS (Two Micron All-Sky Survey), SDSS (Sloan Digital Sky Survey), GALEX (Galaxy Evolution Explorer), and UKIDSS (UKIRT Infrared Deep Sky Survey) surveys in four selected high-latitude $|b|>48^{\circ}$ sky areas are presented. It is shown that multicolor photometric data from large modern surveys can be used for parameterization of stars closer than 4400 pc and brighter than $g_{SDSS} = 19.^m6$, including estimation of parallax and interstellar extinction value. However, the stellar luminosity class should be properly determined.Comment: 11 pages, 5 figure

Physics and Earth Science User Communities of Armenian National Grid Initiative

The main purpose of this article is to present the results and activities of physics and earth sciences heavy user communities of Armenian National Grid Initiative (ArmNGI) using computational or storage resources of Armenian National Grid infrastructure (ArmGrid)

Infrared Spectra and Spectral Energy Distributions for Dusty Starbursts and AGN

We present spectroscopic results for all galaxies observed with the Spitzer Infrared Spectrograph (IRS) which also have total infrared fluxes f(ir) measured with the Infrared Astronomical Satellite (IRAS), also using AKARI photometry when available. Infrared luminosities and spectral energy distributions (SEDs) from 8 um to 160 um are compared to polycyclic aromatic hydrocarbon (PAH) emission from starburst galaxies or mid-infrared dust continuum from AGN at rest frame wavelengths ~ 8 um. A total of 301 spectra are analyzed for which IRS and IRAS include the same unresolved source, as measured by the ratio fv(IRAS 25 um)/fv(IRS 25 um). Sources have 0.004 < z < 0.34 and 42.5 < log L(IR) < 46.8 (erg per s) and cover the full range of starburst galaxy and AGN classifications. Individual spectra are provided electronically, but averages and dispersions are presented. We find that log [L(IR)/vLv(7.7 um)] = 0.74 +- 0.18 in starbursts, that log [L(IR)/vLv(7.7 um)] = 0.96 +- 0.26 in composite sources (starburst plus AGN), that log [L(IR)/vLv(7.9 um)] = 0.80 +- 0.25 in AGN with silicate absorption, and log [L(IR)/vLv(7.9 um)] = 0.51 +- 0.21 in AGN with silicate emission. L(IR) for the most luminous absorption and emission AGN are similar and 2.5 times larger than for the most luminous starbursts. AGN have systematically flatter SEDs than starbursts or composites, but their dispersion in SEDs overlaps starbursts. Sources with the strongest far-infrared luminosity from cool dust components are composite sources, indicating that these sources may contain the most obscured starbursts.Comment: Accepted for publication in The Astrophysical Journa