New Capabilities of One-Meter Schmidt Telescope of the Byurakan Astrophysical Observatory after Modernization

Within the framework of cooperation between Byurakan Astrophysical Observatory and Special Astrophysical Observatory during 2013–2015 y the 1-m Schmidt telescope of the Byurakan Astrophysical was upgraded. We completely redesigned the control system of the telescope: we replaced the actuating mechanisms, developed telescope control software, and made the guiding system. In the Special Astrophysical Observatory the 4k×4k Apogee (USA) liquid-cooled CCD was reworked and prepared. Detector was mounted in the focus of the telescope and provides 1 degree field of view with pixel-size of 0.868, and RON∼11e−. The detector is equipped with a turret with 5 holes for filters. The 20 intermediate-band filters (FWHM= 250A) uniformly covering the 4000–9000 AA wavelength range, five broadband filters (u, g, r, i, z SDSS), and three narrow-band filters. During the first year of test operation of the 1-m telescope we performed pilot observations within the framework of three programs: search for young stellar objects, AGN evolution, and stellar composition of galaxy disks. We confirmed the possibility of efficiently selecting of young objects using observations performed in narrow-band Hα and [S II]filters and the intermediate-band 7500̊Afilter.Three-hours long exposures with SDSS g, r, and i band filters allow us to reach the surface brightness level of 28m from square arcsecond when investigating the stellar content of galaxy disks for a sample of nine galaxies. We used observations performed with the 1-m telescope in five broadband (SDSS u, g, r, i, and z) and 15 intermediate-band filters (4000–7500A) to construct a sample of quasar candidates with 0.5<z<5(330 objects) in about one-sq. degree SA 68 field complete down to RAB=23m. Spectroscopic observations of 29 objects (19.m5<R<22m) carried out at the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences confirmed the quasar nature of 28 objects.

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Narrow band imaging survey of dark clouds

Communications of the Byurakan Astrophysical Observatory ◽

10.52526/25792776-2021.68.2-436 ◽

2021 ◽

pp. 436-440

Author(s):

T. A. Movsessian ◽

T. Yu. Magakyan ◽

S. N. Dodonov ◽

H. R. Andreasyan

Keyword(s):

Narrow Band ◽

Narrow Band Imaging ◽

Young Stellar Objects ◽

Large Field ◽

Main Task ◽

Schmidt Telescope ◽

Stellar Objects ◽

High Quantum Efficiency ◽

Dark Clouds ◽

Infrared Sources

We present new results obtained in frames of the Byurakan Narrow Band Imaging Survey (BNBIS). Observations were carried out with upgraded 1 m Schmidt telescope of Byurakan Observatory. Main task of this survey is to search and to study the new Herbig-Haro objects and collimated outflows using narrow-band Hα and [S ii] images of some fields in dark clouds of Galaxy. And, because, Herbig-Haro objects are the main indicators of active starformation processes to fined regions where going on active starformation processes. Main targets of this survey are R associations, young stellar objects associated with compact reflection nebulae, but here we will mainly focused on deeply embedded infrared sources in molecular clouds. During this survey we plan to significantly expand the list of HH objects by using the high quantum efficiency of the system and the telescopes high focal ratio (F/2), which allows detecting low surface brightness objects as well as large field of view of Schmidt telescope.

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Narrow-band imaging and velocity maps of young stellar objects - Initial results

The Astrophysical Journal ◽

10.1086/184368 ◽

1984 ◽

Vol 285 ◽

pp. L71 ◽

Cited By ~ 4

Author(s):

J. S. Morgan ◽

S. C. Wolff ◽

S. E. Strom ◽

K. M. Strom

Keyword(s):

Narrow Band ◽

Narrow Band Imaging ◽

Young Stellar Objects ◽

Stellar Objects ◽

Initial Results

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New Herbig–Haro objects and outflows in the Mon R1 association

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3302 ◽

2020 ◽

Vol 500 (2) ◽

pp. 2440-2450

Author(s):

T A Movsessian ◽

T Yu Magakian ◽

S N Dodonov

Keyword(s):

Main Sequence ◽

Near Infrared ◽

Narrow Band ◽

Schmidt Telescope ◽

Stellar Objects ◽

Hh Objects ◽

The Mean ◽

Infrared Data

ABSTRACT We present the results of a narrow-band Hα and [S ii] imaging survey of the Mon R1 association performed with the 1-m Schmidt telescope at Byurakan Observatory. Our observations covered a 1° field near the centre of the association. As a result of this study, 20 new Herbig–Haro knots were discovered, some of which form collimated outflows. Among the most extended ones are HH 1203 and HH 1196, which have a length of 1 pc or even more. During the search for the probable sources of HH objects, several new nebulous stars were found. A list of all nebulous stellar objects in the Mon R1 area under study is presented, with detailed descriptions of the most interesting ones. The near-infrared data from the GLIMPSE360 and WISE surveys revealed several more objects related to Mon R1, some of which had optical counterparts, as well as helped to identify at least three probable H2 collimated flows from the deeply embedded pre-main-sequence objects. The probable members of Mon R1 were selected by their distances; their bolometric luminosities and extinctions were estimated. Among the outflow sources, three embedded objects with luminosities greater than 10 L⊙ were found. The mean distance to the Mon R1 complex is estimated as 715 pc.

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Resolved Schmidt-Kennicutt Relation for Star Forming Regions in the Galaxy and Magellanic Clouds

Proceedings of the International Astronomical Union ◽

10.1017/s174392131300149x ◽

2012 ◽

Vol 8 (S292) ◽

pp. 307-310 ◽

Cited By ~ 1

Author(s):

C.-H. R. Chen ◽

R. Indebetouw ◽

E. Muller ◽

M. Messineo ◽

K. M. Menten ◽

...

Keyword(s):

Star Formation ◽

Galaxy Evolution ◽

Formation Rate ◽

Large Magellanic Cloud ◽

Young Stellar Objects ◽

Giant Molecular Clouds ◽

Stellar Content ◽

Stellar Objects ◽

Star Forming ◽

Wide Range

AbstractThe relationship between star formation rate (SFR) and the gas surface density (Σgas) is one of the most critical links between star formation and galaxy evolution. The observed SFR- Σgas relation, the “Schmidt-Kennicutt (S-K) law”, is tight when properties are averaged over kpc, but breaks down at the scale of giant molecular clouds (GMCs). To understand the physics governing the variations at GMC scales and the tight correlation at kpc scales, spatially and temporally resolved data covering a wide range of linear scale are needed. We have used the Spitzer surveys of the Large Magellanic Cloud and Magellanic Bridge to identify massive young stellar objects (YSOs), estimate “instantaneous” SFRs, and compare them to the S-K relation. These instantaneous SFRs are further compared to that estimated from integrated Hα and 24 μm luminosities to examine how SFRs vary on 10 Myr timescales. We have also used SINFONI near-IR integral field spectra of two Galactic mini-starbursts W31 and W43 to determine their underlying massive stellar content, estimate the SFRs, and compare to the S-K relation. To investigate evironmental effects on star formation, we have used complete YSO samples in the LMC and the Bridge to estimate global star formation efficiencies (SFE) in these two systems.

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Dynamics of jet/outflow driven by high-mass young stellar object revealed by KaVA 22 GHz water maser observations

Proceedings of the International Astronomical Union ◽

10.1017/s174392131701167x ◽

2017 ◽

Vol 13 (S336) ◽

pp. 303-304

Author(s):

Jungha Kim ◽

Tomoya Hirota ◽

Kee-Tae Kim ◽

Koichiro Sugiyama ◽

Keyword(s):

Dynamical Evolution ◽

Young Stellar Objects ◽

High Mass ◽

First Year ◽

Stellar Objects ◽

Large Program ◽

Molecular Lines ◽

Water Masers ◽

Initial Results ◽

Water Maser

AbstractWe have started survey observations of the 22 GHz water maser sources associated with high-mass young stellar objects (HM-YSOs) as a part of the KaVA (KVN and VERA Array) large program (LP). The aim of our LP is to understand dynamical evolution of jets/outflows from HM-YSOs by analyzing 3D velocity structures of water maser features. In the first year (2016-2017), an imaging survey toward 25 HM-YSOs has been conducted and the 22 GHz water masers are detected toward 21 sources. Spatial distributions of maser features for individual sources are mapped. To complement physical properties in the vicinity of HM-YSOs, we have carried out ALMA cycle 3 observations of thermal molecular lines and continuum emissions toward 11 selected samples. Summary of the KaVA first year observations and the initial results from the ALMA toward one of our targets, G25.82-0.17, are reported.

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Investigation of the stellar content in the IRAS 05168+3634 star-forming region

Astronomy and Astrophysics ◽

10.1051/0004-6361/201731904 ◽

2019 ◽

Vol 622 ◽

pp. A38

Author(s):

N. M. Azatyan

Keyword(s):

Molecular Cloud ◽

Class Ii ◽

Class I ◽

Young Stellar Objects ◽

Spectral Energy ◽

Evolutionary Stage ◽

Stellar Content ◽

Infrared Excess ◽

Stellar Objects ◽

Star Forming

Aims. We report the investigation results of the structure and content of a molecular cloud surrounding the source IRAS 05168+3634 (also known as Mol 9). Methods. We present a photometric analysis using the data of J, H, K UKIDSS, [3.6], [4.5] μm Spitzer-IRAC and 3.4, 4.6, 12, 22 μm WISE databases. A multi-color criteria was used to identify the candidates of young stellar objects (YSOs) in the molecular cloud; in addition to IRAS 05168+3634, there are four IRAS sources embedded in the same molecular cloud. Color–magnitude diagrams and the K luminosity function (KLF) were used to determine the basic parameters of stellar objects (spectral classes, masses, ages). To study the YSOs with longer wavelength photometry the radiative transfer models were used. Results. Based on color–color and color–magnitude diagrams, we identified a rich population of embedded YSO candidates with infrared excess (Class 0/I and Class II) and their characteristics in a quite large molecular cloud located in a region of 24 arcmin radius. The molecular cloud includes 240 candidates of YSOs within the radii of subregions around five IRAS sources. The local distribution of identified YSOs in the molecular cloud frequently shows elongation and subclustering. The observed young subregions and parental molecular cloud morphologies are similar, especially when only the youngest Class I/0 sources are considered. The color–magnitude diagrams of the subregions suggest a very young stellar population. We construct the KLF of the subregions except for the IRAS 05162+3639 region and it shows unusually low values for α slope: 0.12–0.21. According to the values of the slopes of the KLFs, the age of the subregions can be estimated at 0.1–3 Myr. The spectral energy distributions (SEDs) are constructed for 45 Class I and 75 Class II evolutionary stage YSOs and the received parameters of these YSOs are well correlated with the results obtained by other methods. According to the results of SED fitting tool, the sources IRAS 05184+3635, IRAS 05177+3636, and IRAS 05162+3639 can be classified as Class I evolutionary stage objects. IRAS 05168+3634 and IRAS 05156+3643 can be classified as flat-spectrum objects.

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Accretion Signatures on Massive Young Stellar Objects

Proceedings of the International Astronomical Union ◽

10.1017/s1743921314007327 ◽

2014 ◽

Vol 9 (S307) ◽

pp. 431-436

Author(s):

F. Navarete ◽

A. Damineli ◽

C. L. Barbosa ◽

R. D. Blum

Keyword(s):

Massive Star ◽

Narrow Band ◽

Massive Stars ◽

Young Stellar Objects ◽

Continuum Emission ◽

Stellar Clusters ◽

Low Mass Stars ◽

Stellar Objects ◽

Low Mass ◽

The Continuum

AbstractWe present preliminary results from a survey of molecular H2 (2.12 μm) emission in massive young stellar objects (MYSO) candidates selected from the Red MSX Source survey. We observed 354 MYSO candidates through the H2 S(1) 1-0 transition (2.12 μm) and an adjacent continuum narrow-band filters using the Spartan/SOAR and WIRCam/CFHT cameras. The continuum-subtracted H2 maps were analyzed and extended H2 emission was found in 50% of the sample (178 sources), and 38% of them (66) have polar morphology, suggesting collimated outflows. The polar-like structures are more likely to be driven on radio-quiet sources, indicating that these structures occur during the pre-ultra compact H ii phase. We analyzed the continuum images and found that 54% (191) of the sample displayed extended continuum emission and only ~23% (80) were associated to stellar clusters. The extended continuum emission is correlated to the H2 emission and those sources within stellar clusters does display diffuse H2 emission, which may be due to fluorescent H2 emission. These results support the accretion scenario for massive star formation, since the merging of low-mass stars would not produce jet-like structures. Also, the correlation between jet-like structures and radio-quiet sources indicates that higher inflow rates are required to form massive stars in a typical timescale less than 105 years.

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Exploring the association of Fermi sources with Young Stellar Objects

Proceedings of the International Astronomical Union ◽

10.1017/s1743921310016509 ◽

2010 ◽

Vol 6 (S275) ◽

pp. 406-407

Author(s):

P. Munar-Adrover ◽

J. M. Paredes ◽

G. E. Romero

Keyword(s):

Particle Acceleration ◽

Gamma Rays ◽

Gamma Ray ◽

Surrounding Medium ◽

Theoretical Models ◽

Young Stellar Objects ◽

First Year ◽

Bipolar Outflows ◽

Stellar Objects ◽

Chance Coincidence

AbstractMassive protostars have associated bipolar outflows which can produce strong shocks when interact with the surrounding medium. Some theoretical models predict that particle acceleration at relativistic velocities can occur leading to gamma ray emission. In order to identify young stellar objects (YSO) that might emit gamma rays, we have crossed the Fermi First Year Catalog with catalogs of known YSOs, obtaining a set of candidates by spatial correlation. We have conducted Montecarlo simulations to find the probability of chance coincidence. Our results indicate that ~70% of the candidates should be gamma-ray sources with a confidence of ~5σ.

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