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Extremely strong damped Lyα systems at high redshifts
Journal of Physics: Conference Series. 2020. Vol. 1697. No. 1. Article 012034.
Telikova K. N., Balashev S., Notredaeme P., Krogager J. -., Ranjan A.
We present a spectroscopic analysis of seven Extremely Strong Damped Lyα systems at redshifts z = 2–3, obtained with the intermediate-resolution spectrograph X-shooter on the Very Large Telescope. For all systems we estimated column densities of the neutral atomic hydrogen HI, metal abundances and dust depletion. We firmly detected molecular hydrogen H2 in two systems in our sample; for the remaining systems we set a conservative upper limits on the H2 column densities. The properties of the obtained systems are in consistency with the sample of the Extremely Strong Damped Ly α systems available in the literature.
Balashev S., Ledoux C., Noterdaeme P., Monthly Notices of the Royal Astronomical Society 2020 Vol. 497 No. 2 P. 1946-1956
We present the detection of excited fine-structure energy levels of singly ionized silicon and neutral carbon associated with the proximate damped Lyman-α system at zabs = 2.811 towards Q 0528-250. This absorber has an apparent relative velocity that is inconsistent with the Hubble flow indicating motion along the line-of-sight towards the quasar, i.e. zabs > zem. We ...
Added: February 4, 2022
Klimenko V. V., Balashev S., Monthly Notices of the Royal Astronomical Society 2020 Vol. 498 No. 2 P. 1531-1549
We present the results of an analysis of the physical conditions (number density, intensity of UV field, kinetic temperature) in the cold H2-bearing interstellar medium of local and high-redshift galaxies. Our measurements are based on the fit to the observed population of H2 rotational levels and C I fine-structure levels with the help of grids of ...
Added: February 4, 2022
Balashev S., Kosenko D. N., Monthly Notices of the Royal Astronomical Society: Letters 2020 Vol. 492 No. 1 P. 45-49
We present a semi-analytical description of the relative hydrogen deuteride (HD)/H2 abundance in the diffuse interstellar medium. We found three asymptotics of the relative HD/H2 abundance for different parts of the medium and their dependence on the physical parameters, namely, number density, intensity of the ultraviolet field, cosmic ray ionization rate, and metallicity. Our calculations are in ...
Added: February 4, 2022
Balashev S., Astrophysical Journal Letters 2022 Vol. 926 No. 2 Article L33
We present the discovery of neutral gas detected in both damped Lyα absorption (DLA) and H I 21 cm emission outside of the stellar body of a galaxy, the first such detection in the literature. A joint analysis between the Cosmic Ultraviolet Baryon Survey and the MeerKAT Absorption Line Survey reveals an H I bridge ...
Added: March 31, 2022
Kosenko D. N., Balashev S., Journal of Physics: Conference Series 2020 Vol. 1697 No. 1 Article 012031
We present constraints on physical conditions in diffuse HD/H2-bearing molecular clouds using measured HD/H2 column density ratio. We used recently published formalism that describes how this ratio changes with ultraviolet field intensity, number density and cosmic ray ionization rate. Out of them the most important parameter is the cosmic ray ionization rate, as it determines the ...
Added: February 4, 2022
Kosenko D. N., Balashev S., Noterdaeme P. et al., Monthly Notices of the Royal Astronomical Society 2021 Vol. 505 No. 3 P. 3810-3822
We present a systematic study of deuterated molecular hydrogen (HD) at high redshift, detected in absorption in the spectra of quasars. We present four new identifications of HD lines associated with known H2H2-bearing Damped Lyman-α systems. In addition, we measure upper limits on the HDHD column density in 12 recently identified H2H2-bearing DLAs. We find that the new HDHD detections have ...
Added: February 4, 2022
Noterdaeme P., Balashev S., Krogager J. -. et al., Astronomy and Astrophysics 2021 Vol. 646 Article A108
We present ultraviolet to near infrared spectroscopic observations of the quasar SDSS J001514+184212 and its proximate molecular absorber at z = 2.631. The [O III] emission line of the quasar is composed of a broad (FWHM ∼ 1600 km s-1), spatially unresolved component, blueshifted by about 600 km s-1 from a narrow, spatially-resolved component (FWHM ∼ ...
Added: February 4, 2022
Balashev S., Monthly Notices of the Royal Astronomical Society 2021 Vol. 510 No. 4 P. 5974-5983
We present a spectroscopic investigation with the Very Large Telescope/X-shooter of seven candidate extremely strong damped Lyman-α absorption systems [ESDLAs, N(H I) ≥ 5 × 1021 cm-2] observed along quasar sightlines. We confirm the extremely high column densities, albeit slightly (0.1 dex) lower than the original ESDLA definition for four systems. We measured low-ionization metal abundances ...
Added: March 31, 2022
Noterdaeme P., Balashev S., Ledoux C. et al., Astronomy and Astrophysics 2021 Vol. 651 Article 78
Aims: We aim to study several key physical properties of quasar absorption-line systems that are subtly encoded in their absorption profiles and have not yet been thoroughly investigated or constrained.
Methods: We analysed a high-resolution (R = 140 000) spectrum of the bright quasar HE 0001−2340 (zem = 2.26) obtained with ESPRESSO, which was recently installed at ...
Added: February 4, 2022
Gupta N., Jagannathan P., Srianand R. et al., Astrophysical Journal 2021 Vol. 907 No. 1 Article 11
We present details of the Automated Radio Telescope Imaging Pipeline (ARTIP) and the results of a sensitive blind search for H I and OH absorbers at z < 0.4 and z < 0.7, respectively. ARTIP is written in Python 3.6, extensively uses the Common Astronomy Software Application tools and tasks, and is designed to enable ...
Added: February 4, 2022
Noterdaeme P., Balashev S., Combes F. et al., Astronomy and Astrophysics 2021 Vol. 651 Article A17
We present 3 mm observations of the quasar J0015+1842 at z = 2.63 with the NOrthern Extended Millimeter Array (NOEMA). Our data reveal molecular gas, traced with a Gaussian CO(3-2) line, with a remarkably high velocity dispersion (FWHM = 1010 ± 120 km s−1) that corresponds to a total molecular mass MH2 ≈ (3.4 − 17) ...
Added: February 4, 2022
Balashev S., Gupta N., Kosenko D. N., Monthly Notices of the Royal Astronomical Society 2021 Vol. 504 No. 3 P. 3797-3811
Hydroxyl (OHOH) is known to form efficiently in cold gas (T ~ 100 K) along with the molecule H2H2 and can be used as an efficient tracer of the diffuse molecular gas in the interstellar medium (ISM). Using a simple formalism describing the HI/H2HI/H2 transition and a reduced network of major chemical reactions, we present a semi-analytical prescription to ...
Added: February 4, 2022
Combes F., Gupta N., Muller S. et al., Astronomy and Astrophysics 2021 Vol. 648 Article A116
The Large Survey Project (LSP) "MeerKAT Absorption Line Survey" (MALS) is a blind H I 21 cm and OH 18 cm absorption line survey in the L- and UHF-bands, primarily designed to better determine the occurrence of atomic and molecular gas in the circumgalactic and intergalactic medium, and its redshift evolution. Here we present the ...
Added: February 4, 2022
Kurichin O. A., Kislitsyn P. A., Klimenko V. V. et al., Monthly Notices of the Royal Astronomical Society 2021 Vol. 502 No. 2 P. 3045-3056
The precision measurement of the primordial helium abundance Yp is a powerful probe of the early Universe. The most common way to determine Yp is the analyses of observations of metal-poor H II regions found in blue compact dwarf galaxies. We present the spectroscopic sample of 100 H II regions collected from the Sloan Digital Sky Survey. ...
Added: February 4, 2022
Balashev S., Astronomy and Astrophysics 2022 Vol. 661 Article A134
We present the results of a spectroscopic analysis of extremely strong damped Lyα absorbers (ESDLAs; log N(H I) ≳ 21.7) observed with the medium resolution spectrograph, X-shooter at the Very Large Telescope (VLT). Recent studies in the literature indicate that ESDLAs probe gas from within the star-forming disk of the associated galaxies and thus ESDLAs ...
Added: November 18, 2022
Лигер В. В., Mironenko V., Курицын Ю. А. et al., Квантовая электроника 2022 Т. 52 № 9 С. 831-837
Разработан новый вариант метода диодной лазерной абсорбционной спектроскопии (ДЛАС) для определения температуры горячих зон. Метод основан на комбинации медленного сканирования частоты излучения зондирующего диодного лазера в окрестности линии поглощения тестовой молекулы среды и быстрой модуляции частоты излучения с амплитудой порядка ширины линии поглощения. Особенностью метода является использование двухлучевой дифференциальной схемы, логарифмическое преобразование сигналов и регистрация ...
Added: October 26, 2022
Balashev S., Monthly Notices of the Royal Astronomical Society 2022 Vol. 516 No. 1 P. 1339-1346
We report the emergence of a new H I 21-cm absorption at zabs = 1.172 635 in the damped Lyα absorber (DLA) towards the γ-ray blazar PKS 2355-106 (zem~1.639) using science verification observations (2020 June) from the MeerKAT Absorption Line Survey (MALS). Since 2006, this DLA is known to show a narrow H I 21-cm absorption ...
Added: November 18, 2022
Mapping H I 21-cm in the Klemola 31 group at z = 0.029: emission and absorption towards PKS 2020-370
Balashev S., Monthly Notices of the Royal Astronomical Society 2022 Vol. 516 No. 2 P. 2050-2061
We present MeerKAT Absorption Line Survey (MALS) observations of the H I gas in the Klemola 31 galaxy group (z = 0.029), located along the line of sight to the radio-loud quasar PKS 2020-370 (z = 1.048). Four galaxies of the group are detected in H I emission, and H I absorption is also detected ...
Added: November 18, 2022
Бельведерский М. И., Быков С. Д., Гильфанов М. Р., Письма в Астрономический журнал 2022 Т. 48 № 12 С. 839-851
We have classified the X-ray sources detected by the SRG/eROSITA telescope in the deep Lockman Hole survey. The goal of the classification has been the separation of the sources into Galactic and extragalactic objects. For this purpose, we have used the results of our previous cross-match of Xray sources with optical catalogs. For the classification ...
Added: May 19, 2023
Telikova K. N., Balashev S., Notredaeme P. et al., Monthly Notices of the Royal Astronomical Society 2022 Vol. 510 No. 4 P. 5974-5983
We present a spectroscopic investigation with the Very Large Telescope/X-shooter of seven candidate extremely strong damped Lyman-α absorption systems [ESDLAs, N(H I) ≥ 5 × 1021 cm-2] observed along quasar sightlines. We confirm the extremely high column densities, albeit slightly (0.1 dex) lower than the original ESDLA definition for four systems. We measured low-ionization metal abundances ...
Added: February 4, 2022
Буренин Р. А., Sazonov S., Письма в Астрономический журнал 2016 Т. 42 № 5 С. 277-294
We have compiled a catalog of 903 candidates for type 1 quasars at redshifts 3 < z < 5.5 selected among the X-ray sources of the "serendipitous" XMM-Newton survey presented in the 3XMMDR4 catalog (the median X-ray flux is ≈5 × 10-15 erg s-1 cm-2 in the 0.5-2 keV energy band) and located at high ...
Added: January 27, 2018
Rogachev A., Prutskov G. V., В кн. : Научно-техническая конференция студентов, аспирантов и молодых специалистов НИУ ВШЭ им. Е.В. Арменского. Материалы конференции. : М. : МИЭМ НИУ ВШЭ, 2015. С. 250-250.
В работе описаны особенности проведения исследования органических образцов, сформированных на поверхности жидкости, методами абсорбционной спектроскопии с применением синхротронного излучения. Представлены первые экспериментальные данные. ...
Added: July 22, 2015
S. A. Prokhorenko, S. Yu. Sazonov, Gilfanov M. R. et al., Monthly Notices of the Royal Astronomical Society 2024 Vol. 528 No. 4 P. 5972-5989
We examine the long-term (rest-frame time scales from a few months to ∼20 years) X-ray variability of a sample of 2344 X-ray bright quasars from the SDSS DR14Q Catalogue, based on the data of the SRG/eROSITA All-Sky Survey complemented for ∼7% of the sample by archival data from the XMM-Newton Serendipitous Source Catalogue. We characterise variability by a structure ...
Added: February 1, 2024
Boldyrev K., Молчанова А. Д., Кузьмин Н. Н. et al., Low Temperature Physics 2017 Т. 43 № 6 С. 728-731
Проведено комплексное исследование монокристалла CrBO3 методами оптической и длинноволновой спектроскопии в широком диапазоне температур. Даны фактор-групповой и корреляционный анализы фононных мод. Экспериментально методом нарушенного полного внутреннего отражения обнаружены все ИК активные фононы и установлены их частоты. Выявлен магнитный фазовый переход при темпера-туре 6 К. В магнитоупорядоченном состоянии обнаружена анизотропия оптического спектра при поляри-зационных исследованиях в ...
Added: February 8, 2019