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Project Number19-12-00281

Project titleRCSED v2: a Big Data approach to search unique extragalactic objects and study galaxy evolution mechanisms

Project LeadChilingarian Igor

AffiliationFederal State Budgetary Educational Institution of Higher Education Lomonosov Moscow State University,

Implementation period 2019 - 2021  extension for 2022 - 2023


Research area 02 - PHYSICS AND SPACE SCIENCES, 02-705 - Galaxy and Metagalaxy

Keywordsextragalactic astronomy, galaxy evolution, intermediate mass black holes, data science, big data



The study of the formation and evolution of galaxies and their central black holes remains one of the most important areas of research in modern observational astrophysics. Despite the active development of the international Virtual Observatory concept over the past two decades, the potential of existing astronomical archives and databases for discovery is far from being fully utilized. Our current project aims to search for two rare classes of astronomical objects in astronomical archives and databases: compact early-type galaxies and medium-sized black holes (from 1000 to 100000 solar masses) and the subsequent study of representatives. Understanding their nature is crucial for building a picture of the evolution of galaxies. Our research team is the world leader in observational studies of both classes of objects: in 2009-2018, we found more than 70% of the approximately 230 known compact elliptical galaxies (including 11 out of 13 isolated galaxies) and 5 out of 10 confirmed candidates intermediate mass black holes - all this was done using advanced big data methods applied to large astronomical catalogs and databases. We created a catalog of the spectral energy distributions of 800k RCSED galaxies, which has become the main element in the process of searching and researching objects of these rare classes. In this project, we propose to assemble the second version of this catalog, which we will use to solve the astrophysical tasks we set. It will also become an important element of preparation for the analysis of X-ray data from the SpectrRG / eROSITA space mission, which is scheduled to begin in 2019, since the RCSED v2 catalog will be the most comprehensive catalog of extragalactic objects covering almost the entire Russian area of ​​interest of the eRosita (Eastern Galactic Hemisphere) survey with a uniform analysis of photometric and spectral data. The expansion of the RCSED catalog is planned in several directions: (a) the expansion of the sample of galaxies from 800 thousand to 2.5 million by analyzing the spectra obtained in the 6dFGRS, SDSS-BOSS, SDSS-eBOSS, 2dFGRS surveys; (b) using UHS-J survey data covering the entire northern hemisphere in the near-IR and WISE and Spitzer / IRAC surveys to extend the energy distribution in the spectra in the infrared range to a wavelength of 8 μm; (c) using the full NBursts + phot spectrophotometric analysis of data to reconstruct detailed star formation histories for 2.5 million galaxies; (d) automatic decomposition of the profiles of allowed emission lines in all galaxies that show activity of nuclei in order to determine the masses of black holes; (e) supplementing the RCSED catalog with X-ray data from the Chandra and XMM-Newton catalogs (as well as older data from the ROSAT catalog); (e) Estimation of the masses of clusters of galaxies, which include more than 70-80 spectrally confirmed members, using the caustic method. We expect that, based on the results, we will triple the sample of known black holes of intermediate masses, which will allow us to select suitable candidates for determining the masses of black holes using the reverberation method in optics (using large ground-based telescopes) and ultraviolet (using the Hubble telescope). Expanding the sample of compact elliptical galaxies in three times, especially isolated galaxies, without restrictions on the parameters of stellar populations, will exclude or confirm alternative scenarios for their formation (for example, rapid enrichment with metals in the process of star formation induced by ram pressure, which is a “fresh” scenario of evolution of galaxies discussed theorists without observational evidence). The possible detection of compact elliptical galaxies with active nuclei will make it possible to determine the virial masses of their central black holes, which will give an unequivocal answer to the question about the mass of their progenitors.

Expected results
Our project broadens and extends the research already conducted by our team in the last 7-9 years, which will allow us to specify the formation scenarios of compact galaxies, to confirm or refute alternative scenarios for their formation, and also to answer the question: “What was the mass of central black hole seeds in galaxies in the early universe. ” The project will receive the following methodological and scientific results: 1. The second version of the RCSED v2 spectrophotometric catalog, which will include the results of the analysis of multiwave broadband photometry and spectra of 2.5 million galaxies at redshifts to z = 0.5: properties of stellar populations, history of star formation, dispersion of star velocities, flows in main optical emission lines, star formation rates for galaxies with current star formation, the masses of central black holes for Seyfert (active) galaxies of the first type. 2. The first statistically significant sample of intermediate-mass black holes in galactic nuclei, confirmed by X-ray radiation from accretion disks using archival data (according to our estimates, up to 30 objects), detailed estimates of the environmental parameters of host galaxies for all intermediate-mass black hole candidates (according to our estimates 100,000 objects), the properties of their stellar populations and the status of the current star formation. 3. The first large sample of isolated compact elliptical galaxies without any limitations on the properties of stellar populations: the detection of at least one compact elliptical galaxy of the post-starburst type (with a recently completed starburst) will require the expansion of the generally accepted concept of the origin of compact elliptical galaxies via the tidal stripping of larger progenitor galaxies to alternative models, such as mergers with specific orbit configurations or star formation induced by ram pressure compression in the groups and clusters. 4. The first large catalog of masses of galaxy clusters obtained by the caustic method, which has significantly lower systematic errors than the virial estimates of the masses, which will make it possible to specify the calibration relations for estimating the masses of clusters of galaxies from x-rays of hot gas. All these results are new and each of them separately will be a significant contribution to extragalactic astronomy and exceed the global level of research that will make our project very popular for the astronomical community in Russia and abroad.



Annotation of the results obtained in 2021
We have completed the main part of our RCSEDv2 project and have already used it in scientific projects, some of which we have managed to publish during the reporting period. We collected spectral and photometric datasets for more than 4.7 million galaxies, star clusters and quasars up to redshift z~7 from the publicly available archives. The dataset was homogeneously reduced and several corrections such as telluric, spectrophotometric, aperture, k-correction, etc. were applied to all spectra and photometric measurements. We used the corrected data to carry out spectral analysis of stellar populations and ionized gas in the galaxies using NBursts and IZI techniques. All the results obtained were compiled into catalogs and posted for public access on the project website We prepared the main functionality of the web-service, including parametric and Cone search queries to the database and interactive visualization of the data products. The used technologies allowed us to create a fully interactive web application ( The core features are the exploring the search query output results in the form of a table ( and interactive display of spectra, photometric information and results of spectra analysis on individual pages of the spectrum and galaxy (e.g. NGC 60 galaxy page, The examples of search queries and descriptions of available tables are presented in the documentation page By applying big data analysis techniques to the RCSED catalog, a sample of 11 young low-mass galaxies belonging to Coma cluster (323 million light-years away from Earth) and Abel 2147 (486 million light-years from Earth) was selected. We determined the properties of these objects using simultaneous analysis of spectra and images. Since the star formation had already quenched, it was much easier to predict their future evolution. Images of these galaxies suggest the specific tails of low-density gas and young stars, which were formed due to ram pressure by hot intergalactic gas with temperatures of tens of millions Kelvins present in all galaxies. When low-massive galaxies interacted with hot intracluster plasma, it expelled their own gas, which then formed these structures. The statistical analysis showed that about half of the ultra-diffuse galaxies in the massive Coma cluster were formed this way. For each galaxy studied, the fraction of stars formed as a result of ram pressure was obtained for the first time. These results were published in Nature Astronomy and constituted a part of a master thesis by K.A. Grishin. We developed an analysis workflow of Subaru HyperSuprimeCam survey data to perform an isophotal analysis based on an Astropy-affiliated photutils package to be applied for giant low brightness galaxy candidates. We will use the workflow for assembling an extended sample of low-brightness giant galaxies. We also analysed new deep long-slit optical spectroscopic observations, archival optical images from HyperSuprimeCam survey, and published HI and optical spectroscopic data for a sample of seven gLSBGs. Our sample is not homogeneous by morphology, parameters of stellar populations, and total mass, however, six of seven galaxies sit on the high-mass extension of the baryonic Tully-Fisher relation. Overall, the morphology, internal dynamics, and low star formation efficiency in the outer discs indicate that the three formation scenarios shape gLSBGs: (i) a two-stage formation when an HSB galaxy is formed first and then grows an LSB disc by accreting gas from an external supply; (ii) an unusual shallow and extended dark matter halo; (iii) a major merger with fine-tuned orbital parameters and morphologies of the merging galaxies. These results were published in MNRAS. RCSEDv2 catalog is suitable for sample selection of galaxies of rare types satisfying the most stringent sets of criteria, which was shown even during the demonstration of the very first version of the catalog. In the frame of master thesis of O.P. Gudovskikh. (under the supervision of I.Chilingaryan and A.Afanasyev) we selected a sample of 36 young compact elliptical galaxies and showed that the sample represents a quite diverse population. For example, we found 9 galaxies with inferred tidal structures suggesting a recent tidal stripping event. 6 galaxies demonstrate low density and metallicity of stellar population, and probably are rare tidal dwarf galaxies. Also in 2021, based on the results of our work with the RCSEDv2 catalog, Vladimir Goradzhanov, a 4th (now 5th) year student of the Astronomy Department of the Department of Physics, Moscow State University defended a bachelor theses: "Optical observations of host galaxies of intermediate mass black holes: stellar velocity dispersion, structural characteristics". During the third year of the project we published 4 papers in top-ranked refereed journals (Q1) and 6 papers in the conference proceedings, gave two dozen talks at conferences, seminars and workshops on the topic of the project.



1. Grishin K., Chilingarian I., Afanasiev A., Fabricant D., Katkov I., Moran S., Yagi M. Transforming gas-rich low-mass disky galaxies into ultra-diffuse galaxies by ram pressure Nature Astronomy, Nature Astronomy volume 5, pages 1308–1318 (2021) (year - 2021)

2. Ivan Yu. Katkov, Alexei Yu. Kniazev, Olga K. Sil’chenko, Damir Gasymov Star formation in outer rings of S0 galaxies. IV. NGC 254 – a double-ringed S0 with gas counter-rotation Astronomy & Astrophysics, - (year - 2022)

3. Mazzilli Ciraulo Barbara, Melchior Anne-Laure, Maschmann Daniel, Katkov Ivan Yu., Halle Anaëlle, Combes Françoise, Gelfand Joseph D., Al Yazeedi Aisha Two interacting galaxies hiding as one, revealed by MaNGA Astronomy & Astrophysics, Volume: 653, Article Number: A47 (year - 2021)

4. Saburova A., Chilingarian I., Kasparova A. Sil'chenko O., Grishin K., Katkov I., Uklein R Observational insights on the origin of giant low surface brightness galaxies Monthly Notices of the Royal Astronomical Society, Monthly Notices of the Royal Astronomical Society, Volume 503, Issue 1, pp.830-849 (year - 2021)

5. Chilingarian I., Borisov S., Goradzhanov V., Grishin K., Kasparova A., Katkov I., Klochkov V., Rubtsov E., Toptun V. RCSEDv2: the largest database of galaxy properties from a homogeneously processed multi-wavelength dataset Astronomical Society of the Pacific Conference Series, - (year - 2022)

6. Goradzhanov Vladimir, Chilingarian Igor, Rubtsov Evgenii, Katkov Ivan, Grishin Kirill, Toptun Victoria, Kasparova Anastasia, Klochkov Vladislav, Borisov Sviatoslav RCSEDv2: Processing and analysis of 4+ million galaxy spectra Astronomical Society of the Pacific Conference Series, - (year - 2022)

7. Grishin Kirill, Chilingarian Igor Observing, calibrating and reducing near-infrared imaging mosaics Astronomical Society of the Pacific Conference Series, - (year - 2022)

8. Kasparova Anastasia, Chilingarian Igor, Borisov Sviatoslav, Goradzhanov Vladimir, Grishin Kirill, Katkov Ivan, Klochkov Vladislav, Rubtsov Evgenii, Toptun Victoria RCSEDv2: analytic approximations of k-corrections for galaxies out to redshift z=1 Astronomical Society of the Pacific Conference Series, - (year - 2022)

9. Klochkov V., Katkov I., Chilingarian I., Grishin K., Kasparova A., Goradzhanov V., Toptun V., Rubtsov E., Borisov S. RCSEDv2: Open-source web tools for visualization of imaging and spectral data Astronomical Society of the Pacific Conference Series, - (year - 2022)

10. Toptun Victoria, Chilingarian Igor, Katkov Ivan, Grishin Kirill, Kasparova Anastasia, Borisov Sviatoslav, Rubtsov Evgenii, Goradzhanov Vladimir, Klochkov Vladislav RCSEDv2: homogenization of multi-wavelength photometric data Astronomical Society of the Pacific Conference Series, - (year - 2022)

11. - Под воздействием газа: учёные раскрыли тайну образования ультрадиффузных галактик Russia Today, - (year - )

12. - Межгалактическая плазма лишила ультрадиффузные галактики «топлива» для образования звезд Российский Научный Фонд, - (year - )

13. - Межгалактическую плазму уличили в краже "топлива" у ультрадиффузных галактик Агентство ТАСС, - (year - )

14. - Раскрыта тайна возникновения темных галактик, - (year - )

15. - Межгалактическая плазма лишила ультрадиффузные галактики «топлива» для образования звезд National Geographic Россия, - (year - )

16. - Межгалактическая плазма лишила ультрадиффузные галактики «топлива» для образования звезд Indicator, - (year - )

17. - Раскрыта тайна возникновения темных галактик Rambler, - (year - )

18. - Tails Tell the Tale of Galaxy Evolution Сайт телескопа Subaru, - (year - )

19. - How ultra diffuse galaxies form Сайт лаборатории APC Парижского Университета, - (year - )

20. - Creating Ultra-Diffuse Galaxies Сайт Гарвард-Смитсонианского центра астрофизики, - (year - )

21. - Binospec in Nature Astronomy – See the photo! Сайт обсерватории MMT, - (year - )

22. - Гигантские галактики низкой яркости формируются за счет вещества своих компаньонов?, - (year - )

Annotation of the results obtained in 2019
Our project is devoted to the second data release of the Reference Catalog of Spectral Energy Distribution of galaxies (RCSED v2), which will include the results of the analysis of multiwavelength broadband photometry and the spectra of 4 million galaxies at redshifts up to z = 1, performed by using state-of-art data analysis techniques. Data access to the catalog will be organized through the web service (which right now still contains the first version of the catalog) and through the standard tools of the Virtual Observatory (TAP, SSAP). During the first 7 months of our project, we obtained the following results: 1. Development of the new stellar population models for the spectrophotometric code of analyze of star formation histories NBursts+phot. 2. We established an evolutionary relationship between diffuse post-starburst and dwarf elliptical galaxies. 3. We developed a method for analyzing complex multicomponent profiles of absorption lines in galaxies, taking into account the dynamics of their stellar disсs, using the example of NGC7572. 4. We applied the NBursts+phot technique to the spectral analysis of low surface brightness galaxies. 5. We developed a methodology of an analytical error estimation of the kinematic parameters of galaxies using methods of pixel-by-pixel approximation of spectra, such as NBursts. 6. We began work on the website of RCSEDv2 project (, and we developed tools for visualizing of the galactic spectra. 7. We compiled a full sample of publicly available spectra of galaxies at redshifts from 0 to 1 from large spectral surveys (about 4 million spectra), which we will analyze at further stages of the project.



1. Chilingarian I.V., Grishin K.A., Afanasiev A.V., Fabricant D., Moran S. Evolutionary link between ultra-diffuse galaxies and dwarf early-type galaxies. proceedings of the IAU Symposum 355 The realm of the low-surface-brightness universe, Cambridge University Press, - (year - 2020)

2. Grishin K.A., Chilingarian I.V., Afanasiev A.V., Katkov I. Yu. Reconstructing star formation histories of recently formed ultra-diffuse galaxies Proceedings of the IAU Symposum 355 The realm of the low-surface-brightness universe, Сambridge University Press, в печати (year - 2020)

3. Saburova A.S., Chilingarian I.V., Kasparova A.V., Katkov I.Yu., Sil'chenko O.K., Uklein R.I. Unveiling the origin of giant low surface brightness discs: results of the long-slit spectral observations Proceedings of the IAU Symposum 355 The realm of the ulow-surface-brightness universe, Cambridge University Press, - (year - 2020)

Annotation of the results obtained in 2020
Our project is devoted to the second data release of the Reference Catalog of Spectral Energy Distribution of galaxies (RCSED v2), which will include the results of the homogeneous analysis of multi-wavelength broadband photometry and the spectra of 4 million galaxies at redshifts up to z = 1, performed by using state-of-art data analysis techniques developed by our research team. Data access to the catalog will be organized through the web service and using standard access methods of the Virtual Observatory (TAP, SSAP). In the framework of our project we will present several research topics, which can be advanced using our catalog: (a) search and in-depth study of new compact elliptical galaxies; (b) expanding the sample of intermediate-mass black holes and studies of properties of their host galaxies; (c) expanding the sample of giant low-surface brightness galaxies and studying their characteristics (stellar population, active nuclei). By the end of the second year of our activities we have achieved the following results: 1. We released the first beta-version of the official project web-site that provides a capability of search by different galaxy properties and also contains visualization tools for spectra of galaxies and also their properties (in comparison to large samples) 2. We substantially expanded the functionality of our full spectrum fitting code NBursts+phot by including a possibility of fitting emission and absorption lines in galaxies simultaneously, which allows one to obtain stellar population and ionized gas properties to study gas ionization mechanisms and, in case of active galactic nuclei, estimate the supermassive black hole mass. 3. Unexpectedly, we obtained an interesting phenomenological result that connects star formation in non-barred disk galaxies on local and global scales through the shape of their rotation curves. 4. We found dozens of new giant low-surface brightness disk galaxies in the data from wide-field photometric and spectroscopic surveys.



1. Aouad, Charles J.; James, Philip A.; Chilingarian, Igor V. Coupling local to global star formation in spiral galaxies: the effect of differential rotation Monthly Notices of the Royal Astronomical Society, Volume 496, Issue 4, pp.5211-5226 (year - 2020)

2. Chilingarian, Igor V.; Grishin, Kirill A. Estimating Statistical Uncertainties of Internal Kinematics of Galaxies and Star Clusters Derived Using Full Spectrum Fitting Publications of the Astronomical Society of the Pacific, Volume 132, Issue 1012, id.064503, 9 pp. (year - 2020)

3. Coppejans, D. L.; Margutti, R.; Terreran, G.; Nayana, A. J.; Coughlin, E. R.; .... ; Chilingarian, I. V. et. al A Mildly Relativistic Outflow from the Energetic, Fast-rising Blue Optical Transient CSS161010 in a Dwarf Galaxy The Astrophysical Journal Letters, Volume 895, Issue 1, id.L23, 15 pp. (year - 2020)

4. Ianjamasimanana, Roger; Namumba, Brenda; Ramaila, Athanaseus J. T.; Saburova, Anna S.; Józsa, Gyula I. G.; Myburgh, Talon; Thorat, Kshitij; Carignan, Claude et. al MeerKAT-16 H I observation of the dIrr galaxy WLM Monthly Notices of the Royal Astronomical Society, Volume 497, Issue 4, pp.4795-4813 (year - 2020)

5. Kasparova, Anastasia V.; Katkov, Ivan Yu; Chilingarian, Igor V. An excessively massive thick disc of the enormous edge-on lenticular galaxy NGC 7572 Monthly Notices of the Royal Astronomical Society, Volume 493, Issue 4, p.5464-5478 (year - 2020)

6. Maschmann, Daniel ; Melchior, Anne-Laure ; Mamon, Gary A. ; Chilingarian, Igor V. ; Katkov, Ivan Yu. Double-peak emission line galaxies in the SDSS catalogue. A minor merger sequence Astronomy and Astrophysics, Volume: 641, Article Number: A171 (year - 2020)

7. Mink, Jessica; Brown, Warren R.; Chilingarian, Igor V.; Fabricant, Daniel; Kurtz, Michael J.; Moran, Sean; Rhee, Jaehyon; Tokarz, Susan; Wyatt, William F. Center for Astrophysics Optical Infrared Science Archive. I. FAST Spectrograph The Astronomical Journal, Volume 161, Issue 1, id.3, 12 pp. (year - 2021)

8. Raymond, John C.; Chilingarian, Igor V.; Blair, William P.; Sankrit, Ravi; Slavin, Jonathan D.; Burkhart, Blakesley Turbulence and Energetic Particles in Radiative Shock Waves in the Cygnus Loop. I. Shock Properties The Astrophysical Journal, Volume 894, Issue 2, id.108, 13 pp. (year - 2020)

9. Raymond, John C.; Slavin, Jonathan D.; Blair, William P.; Chilingarian, Igor V.; Burkhart, Blakesley; Sankrit, Ravi Turbulence and Energetic Particles in Radiative Shock Waves in the Cygnus Loop. II. Development of Postshock Turbulence Astrophysical Journal, Volume 903, Issue 1, id.2, 19 pp. (year - 2020)

10. Zasov, Anatoly V.; Saburova, Anna S.; Egorov, Oleg V.; Moiseev, Alexey V. NGC 90: a hidden jellyfish galaxy? Monthly Notices of the Royal Astronomical Society, Volume 498, Issue 1, pp.101-109 (year - 2020)

11. - В группе нет ни одного человека, кто занимался бы единственным проектом, - (year - )