Camera lens for the 6-m Russian telescope fiber-optic magnetometer

We have designed and produced a speed camera lens for fiber-optic magnetometer of the prime focus of the 6-m Russian telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. Resolution of the developed lens obtained during test observations corresponds to the calculated value. The transmission of the lens was measured at three wavelength ranges. It is equal to 78% at a wavelength of 6328 Å, 80% at λ 5320 Å, and 19% at λ 4050 Å. A transmission cutoff for wavelengths shorter than 430 nm is outside the operational range of the spectrograph of the fiber-optic magnetometer which is 430–690 nm.     

Fiber-optic magnetometer for prime focus of 6-m BTA telescope based on suspended echelle spectrograph

We have developed and manufactured a fiber-optic magnetometer for the prime focus of the 6-m BTA telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences based on a suspended echelle spectrograph. The magnetometer is designed to improve the spectrum stability and eliminate the effect of instrumental polarization of the diagonal mirror on the results of magnetic field measurements. The magnetometer is to be used for measurements of stellar magnetic fields in stars and to study their chemical composition. The instrument operates in the 5000–6800 Å wavelength interval with mean reciprocal dispersion of 0.15 Å/pixel. According to the estimates for 9 ^m .5 stars, the standard error of magnetic field measurements based on 400 spectral lines would be 100 G for a half-hour exposure.     

ADAM low- and medium-resolution spectrograph for 1.6-m AZT-33IK telescope

We describe the design of a suspended low- and medium-resolution spectrograph (R ≈ 300–1300) designed and made at the Special Astrophysical Observatory of the Russian Academy of Sciences for the 1.6-m AZT-33IK telescope of Sayan Observatory of the Institute of Solar-Terrestrial Physics of the Siberian Branch of the Russian Academy of Sciences. We report the results of laboratory measurements of the parameters of the instrument and tests performed on the 1-m Zeiss-1000 telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We measured the total quantum efficiency of the “spectrograph + telescope + detector” system on AZT-33IK telescope, which at its maximum reaches 56%. Such a hight transparency of the spectrograph allows it to be used with the 1.6-m telescope to determine the types and redshifts of objects with integrated magnitudes m_AB ≈ 20–21, and this result was confirmed by actual observations.     

Independent estimate of the interstellar extinction toward FU Ori

Speckle-interferometric observations of FU Ori are performed with the 6-m telescope of the Special Astrophysical Observatory with 600/40 nm and 800/100 nm (central bandwidth/halfwidth) filters. The companion star FU Ori S that was recently discovered at λ >-1.25µm was recorded in observations with the λ/Δλ==800/100 nm filter. The positional parameters and magnitude difference of the companion in the filter considered are found to be θ = (163.9 ± 1.0)°, ρ = (0.493 ± 0.007)″, Δm = 3.96 ± 0.28. An analysis of the spectral energy distribution of the companion implies that for the extinction A _V toward FU Ori to be greater than about 1.6 ^m , i.e., the minimum value required by the available models of the fuor, the spectral type of the companion star must be no later than K3. The reliability of this conclusion and the possible ways for obtaining more accurate estimates of A _V are discussed.     

Detection of the binarity of the star J1158+4239

One of the goals of the Pulkovo program of research on stars with large proper motions is to reveal among the low-luminosity stars those that have evidence of binarity. Twelve astrometric binary candidates from the Pulkovo list have been included in the program of speckle observations with the BTA telescope at the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS) and the 2.5-m telescope at the Caucasus Observatory (CO) of the Sternberg Astronomical Institute of the Moscow State University to confirm their binarity and then to determine the parameters of the revealed stellar pairs. The binarity of the brightest of these stars, J1158+4239 (GJ 3697), has been confirmed. Four sessions of speckle observations with the BTA SAO RAS telescope and one session with the 2.5-m CO telescope have been carried out in 2015–2016. The weighted mean estimates of the pair parameters are ρ = 286.5 ± 1.2 mas and θ = 230.24? ± 0.16? at the epoch B2015.88248. The magnitude difference between the pair stars is Δm = 0.55 ± 0.03 (a filter with a central wavelength of 800 nm and a FWHM of 100 nm) and Δm = 0.9 ± 0.1 (an R filter).     

A photometric study of faint galaxies in the field of GRB 000926

We present our B, V, R_c, and I_c observations of a \(3'.6 \times 3'\) field centered on the host galaxy of GRB 000926 (α_2000.0=17^h04^m11^s, \(\delta _{2000.0} = + 51^ \circ 47'9\mathop .\limits^{''} 8\)). The observations were carried out on the 6-m Special Astrophysical Observatory telescope using the SCORPIO instrument. The catalog of galaxies detected in this field includes 264 objects for which the signal-to-noise ratio is larger than 5 in each photometric band. The following limiting magnitudes in the catalog correspond to this limitation: 26.6 (B), 25.7 (V), 25.8 (R), and 24.5 (I). The differential galaxy counts are in good agreement with previously published CCD observations of deep fields. We estimated the photometric redshifts for all of the cataloged objects and studied the color variations of the galaxies with z. For luminous spiral galaxies with M(B)z～1.     

Evolutionary status and chemical composition of the atmosphere of the spectroscopic and speckle interferometric binary HD 10009

HD 10009 is a spectroscopic and speckle interferometric binary with almost identical solar-type components. It was studied via speckle interferometry using the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences and had its spectrophotometry performed in the 3500–9600 Å wavelength interval with the 2-m telescope of the Terskol Branch of the Institute of Astronomy of the Russian Academy of Sciences. A detailed analysis of the atmosphere of the primary component (component 1) of the binary yielded the abundances of some of the elements. The luminosities and temperatures of the components are found to be L ₁= 2.9 L _⊙, L ₂= 1.0 L _⊙ and T _eff1=6017 K, T _eff2=5930 K, respectively. The iron abundance is [Fe]=?0.27±0.05. Our results make it possible to assess the evolutionary status of the system. The binary is 7.9 Gyr old and the primary component is close to become a red giant, whereas the secondary component is still in the hydrogen-burning stage near the main sequence.     

Detailed optical spectroscopy of the B[e] Star MWC17

Based on the material of multiple high-resolution R = 60 000 observations conducted on the 6-m telescope (BTA) of the Special Astrophysical Observatory in combination with the Nasmyth Echelle Spectrograph (NES), we closely studied the features of the optical spectrum of the star MWC17 with the B[e] phenomenon. In the wavelength interval of 4050–6750 Å, we identified numerous permitted and forbidden emissions, interstellar Na I lines, and diffuse interstellar bands (DIBs). Radial velocities were estimated from lines of different origin. As the systemic velocity, V_sys, the velocity of the forbidden emissions can be accepted: ?47 kms^?1 (relative to the local standard V_lsr = ?42 kms^?1). Comparison of the obtained data with the earlier measurements allows us to conclude on the absence of considerable variability of spectral details.     

The structure of clusters with bimodal distributions of galaxy radial velocities. II: A1775

We analyze the structure of the cluster of galaxies Abell 1775 (α = 13 ^h 42 ^m , δ = +26°22′, cz ≈ 21000 km/s), which exhibits a bimodal distribution of radial velocities of the containing galaxies. The difference of the subcluster radial velocities is ΔV ≈ 2900 km/s. We use the results of our photometric observations made with the 1-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences and the spectroscopic and photometric data from the SDSS DR6 catalog to determine independent distances to the subclusters via three different methods: the Kormendy relation, photometric plane, and fundamental plane. We find that the A1775 cluster consists of two independent clusters, A1775A (cz = 19664 km/s) and A1775B (cz = 22576 km/s), each located at its own Hubble distance and having small peculiar velocities. Given the velocity dispersions of 324 km/s and 581 km/s and the dynamic masses within the R ₂₀₀ radius equal to 0.6 × 10¹⁴ and 3.3 × 1014 M _⊙, the A1775A and A1775B clusters have the K-band luminosity-to-mass ratios of 29 and 61, respectively. A radio galaxy with an extended tail belongs to the A1775B cluster.     

The Excess Density of Field Galaxies near <Emphasis Type="Italic">z</Emphasis> ~ 0.56 around the Gamma-Ray Burst GRB021004 Position

We test for reliability any signatures of field galaxies clustering in the GRB021004 line of sight. The first signature is the GRB021004 field photometric redshifts distribution based on the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences observations with a peak near z ~ 0.56 estimated from multicolor photometry in the GRB direction. The second signature is the Mg II λλ2796, 2803 Å absorption doublet at z ≈ 0.56 in VLT/UVES spectra obtained for the GRB021004 afterglow. The third signature is the galaxy clustering in a larger (of about 3° × 3°) area around GRB021004 with an effective peak near z ~ 0.56 for both the spectral and photometric redshifts from a few catalogs of clusters based on the Sloan Digital Sky Survey (SDSS) and Baryon Oscillation Spectroscopic Survey (BOSS) as a part of SDSS-III. From catalog data the size of the whole inhomogeneity in distribution of the galaxy cluster with the peak near z ≈ 0.56 was also estimated as about 6°–8° or 140–190 Mpc. A possibility of inhomogeneity (a galaxy cluster) near the GRB021004 direction can be also confirmed by an inhomogeneity in cosmic microwave background related with the Sunyaev–Zeldovich effect.     

Investigation of Galaxies of the Second Byurakan Sky Survey. IV. Spectroscopic Observations in the Fields of 11h30m, +59° and 12h00m, +59°

Spectroscopic observations of 71 objects have completed the follow-up spectroscopy of galaxies in two adjacent fields of the Second Byurakan Survey with central coordinates = 11^h30^m, = +59° and = 12^h00^m, = +59°. The spectra were obtained on the 2.6-m telescope of the Byurakan Astrophysical Observatory and the 6-m telescope of the Special Astrophysical Observatory. The redshifts and absolute stellar magnitudes of all the galaxies have been determined. The objects have been classified using an adapted scheme.     

Investigation of Galaxies of the Second Byurakan Sky Survey. III. Spectroscopic Observations in the Fields of 09h47m, +51° and 09h50m, +55°

The results of observations of 49 objects from the second Byurakan spectroscopic sky survey are given; they complete the recent spectroscopy of galactic samples in the fields centered on the coordinates = 09^h47^m, = +51° and = 09^h50^m, = +55°. The spectra were obtained on the 2.6-m telescope of the Byurakan Astrophysical Observatory, National Academy of Sciences of the Republic of Armenia, and the 6-m telescope of the Special Astrophysical Observatory, Russian Academy of Sciences, during 1998-2000. Redshifts and absolute stellar magnitudes were determined for all the galaxies.     

The structure of clusters with bimodal distributions of galaxy radial velocities,I. A1035

The structure of the A1035 cluster of galaxies (10^h32^m + 40°13′, cz ～ 22000 kms^?1), which exhibits a bimodal distribution of galaxy radial velocities (ΔV ≈ 3000 kms^?1), is analyzed using three methods of determining the relative distances to clusters from early-type galaxies: the Kormendy relation corrected for the dependence of residuals on galaxy magnitude, the photometric plane, and the fundamental plane. We use the data obtained with the l-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences and SDSS (DR5) data to show that A1035 consists of two gravitationally unbound independent clusters. These clusters with the velocity dispersions of 566 km s^?1 and 610 km s^?1 and masses within R ₂₀₀ equal to 2.7 · 10¹⁴ and 3.5 · 10¹⁴ M _⊙, respectively, obey the Hubble law.     

Some features of the radial-velocity variations of lines of different intensity in the spectrum of HD 93521. Variability of the stellar wind

CCD spectra taken with the PFES echelle spectrograph of the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences are used to perform a detailed study of the variability of the profiles of Hell, Hβ, and Hα lines in the spectrum of HD 93521. The pattern and nature of the variability of the Hell lines are similar to those of weak HeI lines and are due to nonradial pulsations. The period and amplitude of the radial-velocity variations are the same for the blue and red halves of the absorption profile but their phases are opposite. The behavior of the variations of Hβ and Hα hydrogen lines relative to their mean profiles is the same as that of strong HeI line and is due to nonradial pulsations. The period and phase of the radial-velocity oscillations are the same for the blue and red halves of the absorption profile but their amplitude are different. The behavior of the radial-velocity variations of the absorption and emission components of the Hα line indicates that the latter also are caused by nonradial pulsations. All this is indicative of the complex structure of the stellar wind in the region of its origin. The behavior of variability and wind kinematics differ in different directions and for different regions of the atmosphere and/or envelope.     

Observational study of the candidate polar-ring galaxies NGC 304 and NGC 7625

We present the results of our photometric (BV R) and spectroscopic CCD observations of NGC 304 and NGC 7625, candidate polar-ring galaxies, performed with the 6-m Special Astrophysical Observatory telescope. For NGC 304, such a study has been carried out for the first time. We have obtained basic integrated characteristics of the galaxies and determined their morphological types (S0 for NGC 304 and Sa for NGC 7625). The absolute magnitudes of the galaxies, M _B = ?20^m.81 for NGC 304 and M _B = ?19^m.34 for NGC7625, are indicative of their fairly high luminosities. The disk and bulge parameters have been determined forNGC 304 (µ₀ = 20^m.60, h = 3.86 kpc, µ _e = 21^m.59, r _e = 1.26 kpc in the B band); these correspond to the parameters of S0-type objects. The rotation velocity for NGC 304 (200 km s^?1) reaches its maximum at a galactocentric distance of 3.1 kpc, which yields a mass estimate for the galaxy of 2.8 × 10¹⁰ \(\mathcal{M}_ \odot \). The observed photometric features at the center of NGC 304 indicate that it may have an inner ring structure, although we have failed to confirm the existence of two kinematic systems based on our spectroscopic observations. In NGC 7625, the disk makes a dominant contribution to the total brightness. The derived integrated color indices (B-V = 0^m.81 and V-R = 0^m.61) agree with previous determinations of other authors. We have estimated the учештсешщт in the inner galactic regions. In the outer regions, we have detected structures with bluer colors (B-V = 0^m.60), which may be indicative of a polar ring with a minor stellar component.     

New spectroscopic observations of the post-AGB star V354 Lac = IRAS 22272+5435

The strongest absorption features with the lower-level excitation potentials χ _low < 1 eV are found to be split in the high-resolution optical spectra of the post-AGB star V354 Lac taken in 2007–2008 with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. Main parameters, T _eff =5650 K, log g=0.2, ξ _t =5.0 km/s, and the abundances of 22 chemical elements in the star’s atmosphere are found. The overabundance of the s-process chemical elements (Ba, La, Ce, Nd) in the star’s atmosphere is partly due to the splitting of strong lines of the ions of thesemetals. The peculiarities of the spectrum in the wavelength interval containing the LiI λ 6707 Å line can be naturally explained only by taking the overabundances of the CeII and SmII heavy-metal ions into account. The best agreement with the synthetic spectrum is achieved assuming ?(LiI)=2.0, ?(CeII)=3.2, and ?(SmII)=2.7. The velocity field both in the atmosphere and in the circumstellar envelope of V354 Lac remained stationary throughout the last 15 years of our observations.     

<Emphasis Type="Italic">UVR</Emphasis> CCD photometry of stars in five sky areas with matched IR/radio sources

Five sky areas about the radio sources ICRS 1254+571, ICRS 1345+125, ICRS 1641+399, ICRS 1732+389, and ICRS 1807+698 were observed with the aim to identify reliably the extragalactic radio sources in these areas with bright infrared objects and objects in the optical range. The test CCD observations were made in the U, V, and R bands of the Johnson system with the 2-meter telescope of the Terskol Peak Observatory (North Caucasus, Russian Federation). The U, V, and B magnitudes and the equatorial coordinates α and δ in the USNO-A2.0 catalog system were determined for objects down to V ≈ 23^m in 8.5′ × 8.5′ areas, and these objects were identified with stars and infrared objects in the 2MASS catalog. The CCD image processing realized within the MIDAS/ROMAFOT program package on the basis of a new method for flat-field elimination is briefly described.     

Chemical composition of high proper-motion stars based on short-wavelength optical spectra

The results of spectroscopic observations made with the NES echelle spectrograph of the 6-m BTA telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences in the wavelength interval of 3550–5100 Å with a spectral resolution of R≥50000 are used to determine the fundamental parameters and atmospheric abundances of more than 20 chemical elements including heavy s- and r-process elements from Sr to Dy for a total of 14 metal-poor G-K-type stars. The abundances of Mg, Al, Sr, and Ba were calculated with non-LTE line-formation effects accounted for. The inferred overabundance of europium with respect to iron agrees with the results obtained for the stars of similar metallicity. The chemical composition of the star BD+80°245 located far from the Galactic plane is typical of stars of the accreted halo: this star exhibits, in addition to the over-deficiency of α-process elements, also the over-deficiency of the γ-process element Ba: [Ba/Fe]= ?1.46. The kinematical parameters and chemical composition imply that the stars studied belong to different Galactic populations. The abundance of the long-living element Th relative to that of the r-process element Eu is determined for six stars using the synthetic-spectrum method.     

Investigation of the spectroscopic variability of the Wolf-Rayet star HD 192163

Based on 24 high-resolution echelle spectrograms of the Wolf-Rayet star HD 192163 taken in 2005–2007 at the Cassegrain focus of the 2-m Zeiss-2000 telescope at the Shemakha Astrophysical Observatory (National Academy of Sciences of Azerbaijan), we have investigated the profiles of five emission lines: He II 4859, He II 5411, CIV 5808, He I 5875, (He II + Hα) 6560. We have analyzed the echelle spectrograms using the DECH20 code. Various emission line parameters have been determined: the equivalent widths, radial velocities, central intensities, and FWHMs. The violet wing of the He II + Hα emission band has been found to be variable (from 6496 Å to 6532 Å). Significant differences in the equivalent widths and radial velocities of the He II + Hα emission band in 2005 and 2007 were revealed. This can be a manifestation of long-term variations in the star HD 192163. We have confirmed that HD 192163 belongs to the WN6 spectral subtype.     

Optical spectroscopy of candidates for quasars at 3 &lt; <Emphasis Type="Italic">z</Emphasis> &lt; 5.5 from the XMM-newton X-ray survey. A distant X-ray quasar at <Emphasis Type="Italic">z</Emphasis> = 5.08

We present the results of optical spectroscopy for 19 quasar candidates at photometric redshifts z _phot ? 3, 18 of which enter into the Khorunzhev et al. (2016) catalog (K16). This is a catalog of quasar candidates and known type 1 quasars selected among the X-ray sources of the 3XMM-DR4 catalog of the XMM-Newton serendipitous survey. We have performed spectroscopy for a quasi-random sample of new candidates at the 1.6-m AZT-33IK telescope of the Sayan Solar Observatory and the 6-m BTA telescope of the Special Astrophysical Observatory. The spectra at AZT-33IK were taken with the new low- and medium-resolution ADAM spectrograph that was produced and installed on the telescope in 2015. Fourteen of the 18 candidates actually have turned out to be quasars; 10 of them are at spectroscopic redshifts z _spec > 3. The high purity of the sample of new candidates suggests that the purity of the entire K16 catalog of quasars is probably 70–80%. One of the most distant (z _spec = 5.08) optically bright (i′ ? 21) quasars ever detected in X-ray surveys has been discovered.