Accreting compact objects result in some of the most spectacular phenomenology in the Universe. Novae and supernovae, quasars and blazars, and many highly energetic phenomena result from accretion onto black holes, neutron stars and white dwarfs. These sources divide naturally into two categories, namely accreting compact binaries (where “compact” refers to the nature of the accreting star) and AGN, which display accretion onto a supermassive black hole. While these two categories of sources differ by many orders of magnitude in their masses and scales, they display remarkably similar physical processes. Since black holes accretion disks are very hot and ionized, consequently, so magnetic field has an important role in the structure and dynamics of accretion flow. Over the last10 years we examined the role of B-field (with different geometry) in the structure and dynamics of AD by including different physical processes such as magnetic resistivity, thermal conduction and wind/outflow. In this meeting I will present some of our results. Theoretical studies on black-hole accretion flows were initiated in the 1960's and a classical picture of accretion disks was established by the early 1970's. Much of the astronomical community’s huge investment in high-energy astrophysics, including orbiting X-ray and gamma-ray observatories and ground-based air shower arrays, is motivated by studying accretion onto compact objects and the wide variety of phenomena so produced. However, required some another type of disk models distinct from the classical one. As a model to meet this requirement, advection-dominatedaccretion flows appeared before the footlights and were extensively studied in the 1990's.
For investigation and understand Blazars properties we take catalogs Blazars. In this catalog we can't say which criteria must be have sources for included in this catalog. For understand and get that criteria we get this catalog for investigation. Catalog Blazars (5 edition) have 3561 sources. This catalog included 4 types of blazars (BZB, BZG, BZQ and BZU). Investigation this catalogs opportunity to say in this catalogs all sources have radio radiation, 63% have X-ray radiation and 28 % have gamma-ray radiation. This catalog cross-correlation with USNO A2.0, USNO B1.0, GSC 2.3.2 and APM. We can say 48 % (1698 sources) have variability in optical range and 3 % (98 sources) have high variability in optical range.
Distant, highly luminous quasars are important cosmological probes for a variety of astrophysical questions: the first generation of galaxies, the star formation history and metal enrichment in the early Universe, the growth of the first super massive black holes (SMBHs), the role of feedback from quasars and SMBHs in galaxy evolution, the epoch of reionization, etc. In addition, they are used as background illuminating source that reveal any object located by chance on the line of sight. I will present our group works in these issues that can be done using absorption lines in the quasar spectra.
Importance of the Sun for life on Earth has long been recognized. Particularly noticeable in sub-tropical latitudes where Sun's energy is strongest.
Heliophysics: A newly emerged Science making the link between Solar physics (study of the sun, its atmosphere and its magnetic activity) and solar-terrestrial Relationships (includes heliospherical phenomena). Now extended to a new< space weather> science at NASA:LWS, a 10 US G$ program defined as:
Living With a Star is a cross-cutting program whose goals and objectives have the following links to each of the four NASA Strategic Enterprises:
1-Space science : LWS quantifies the physics, dynamics, and behavior of the sun-Earth system over the 11-year solar cycle.
2-Earth science: LWS improves understanding of the effects of solar vaiability and disturbances on terrestrial climate change.
3-Himan Exploration and Development: LWS provides data and scientific understanding required for advanced warning of energetic particle events that affect the safety of humans.
4-Aeronautics and Space Transportation: LWS provides detailed characterization of radiation environements useful in the design of more reliable electronic components for air and space transportation systems.
In this talk, we will present and discuss about some consequences of space weather as:
Aeronautics (High altitude aircraft exposure to radiation, especially near the Poles and Navigational and GPS interference).
Astronautics (Threat of sporadic radiation to astronauts, potential damage to spacecraft electronics). Scientificaly, understand how the sun works; understand how Geospace responds to solar and heliospheric variations.
Technology Infrastructure (Distruption/failure of communication satellites; Power grid disruption problems/equipment failure.
Climate Change (Global temperature variations; predictive capability for climatic changes).
The Yohkoh even more, the SoHO mission help to realize the threats тАж
It has been shown that normal radio pulsars are not distributed symmetrically relative to the plane of the Galaxy. Moreover, in the directions to the Galactic center the plane of symmetry of pulsars is higher than galactic plane on average of 50ps, and towards anticentre - on average of 100ps below of this plane. Distribution of all pulsars relative to the plane of the Galaxy can be represented by an exponential function with a characteristic distance about 300ps from the galactic plane. The characteristic distance increases within 130ps - 420ps, depending on the age of the pulsar. In the distribution of the surface density of pulsars is observed a maximum at the distances from the Galactic centre of about 3-4kps. The density of pulsars in the central region of the galaxy is about the same as in the vicinity of the sun.
We present results of simultaneous profile variations in the broad Ha, Hb and Hg lines in the nucleus of Markarian 6 on time scale of hour. Observations were made at two telescopes - the 6-m telescope of the SAO (Russia), equipped with a TV scanner, and the 2.6-m telescope of the BAO (Armenia), using ByuFOSC camera with the CCD receiver. Total of 12 spectra were obtained in 1991 and 2008. Intranight profile variations are important to look for the characteristic variability signatures of different kinematical models of the BLR of AGN. Detected profile changes take the form of narrow , small bumps located at the blue and red sides of indicated lines with the same radial velocity shifts. These rapid variations may be associated with the response of circularly rotating hydrogen clouds in the BLR to a light pulse from a central source of AGN. In addition, it has been shown that several changes possibly indicate the presence of anisotropic ionization radiation in the central source. Simultanous observation of such variations in several lines greatly enhances a reliability of these conclusions. Note that the variability is at least 2 orders of magnitude more rapid than any observed for broad Balmer line profiles in AGNs that we are aware of in the literature.
The results of the searching on the bases of GPS UKIDSS survey's data of dense compact stellar clusters in the vicinity of 19 YSOs with high and middle masses are presented. Totally we have revealed clusters in 12 areas. Around 5 objects (IRAS 18151−1208, IRAS 18316−0602, IRAS 19110+1045, IRAS 19213+1723, IRAS 20056+3350) they are newly detected. The clusters associated with IRAS 05168+3634, IRAS 20188+3928, IRAS19374+2352 and IRAS19388+2357 sources have been already revealed on the less depth data than GPS UKIDSS survey images. The compact groups of stars located in the vicinity of IRAS 05358+3543, IRAS 18507+0121 and IRAS 20198+3716 sources belong to the more extensive clusters. The radii and stellar density have significant gradient: from 0.2 to 2.7 pc and from 3 to 1000 stars/pc2 respectively. In the vicinity of 7 IRAS sources (IRAS18174−1612, IRAS18360−0537, IRAS18385−0512, IRAS18517+0437, IRAS19092+0841, IRAS19410+2336, IRAS 20126+4104) the stellar clusters were not revealed.
As the satellites have a multiple role in the humans' life, being damaged and therefore failure of their segment causes problems and lots of expenses, so evaluating different types of failures in their segments has a crustal role. Solar particles are one of the most important reasons of segment damages during a solar event or in the usual times. During a solar event these particle may cause extensive damages which are even permanent. To avoid these effects and design shielding mediums, we need to know SEP (solar energetic particles) flux and MTTF (mean time between two failures) of segments. In the present work, we calculated SEP flux witch collides the satellite in common times in different altitude and different orbits above the atmosphere. OMERE software was used to determine the coordinates and specifications of a satellite which in simulations has been launched to space. Then we designed an electronic computer and calculated MTTF for it with a mathematical and statistical approach. In the same way the SEP flux were calculated during different solar flares of different solar cycles and MTFF were evaluated during occurring of solar flares. Thus a relation between solar flare energy (erg) and life time of satellite electronic computer (hours) in different orbits were obtained.
The Lensing of the cosmic Microwave background (CMB) radiation is a new and promising cosmological observation to study the physics of the early universe (EU). The standard model of cosmology known as LCDM with the initial conditions of nearly scale invariant, nearly Gaussian and isotropic, describe the cosmological observations such as CMB with a good accuracy. However in order to probe any deviation from the standard initial conditions and open new windows to the physics of EU, we need observations which can probe the evolution of cosmological perturbations in sub- CMB scales like CMB lensing. In this talk I will describe how this effect can be used as a probe to study the deviation from standard case. (Deviations such as dipole asymmetry, the existence of the feature in primordial power spectrum and etc). Finally I discuss how the CMB lensing with cosmic shear data can help to improve our constraints on the deviation from standard initial conditions.
As we know the two oldest Armenian calendars- the Haykian and Protohaykian calendars have different durations of year. The year in the Haykian calendar consists of 360 days, while the year of Protohaykian calendar has only 300 days. Parallel to the astronomical explanation of this difference another – “ideological” explanation is suggested. These two canonic durations of the year may be developed as a result of comparison of 30-day lunar month and the solar year on the basis of two different calculation systems. The idea of 300-day year was a result of Moon/Sun relation on the basis of decimal system. On the other hand the 360-day year idea was developed as a result of the same relation on the basis of duodecimal notation system.
Observing the first DIBs, in the spectra of reddened stars, by Heger (1922) was the starting point to the oldest puzzle in stellar spectroscopy that still remains unresolved. At the present, the DIBs are known to comprise 500 narrow to broad interstellar absorption features, which are observed ubiquitously between 4000 and 10000 Å (Herbig 1995). Over the last decade, many astronomical and laboratory experiments have been accomplished to find and understand DIB carriers as well as a number of theoretical studies. There are still ambiguities about DIB carriers. Specific groups of UV-resistant molecules, such as polycyclic aromatic hydrocarbons (PAHs), fullerenes, and carbon chains are commonly the more acceptable candidates for DIB carriers (Herbig 1995). We are doing a large survey with the UVES instrument on the Very Large Telescope (VLT) operated by ESO at Paranal Observatory in Chile, to study the carrier of DIBs. This project is named "ESO Diffuse Interstellar Bands Large Exploration Survey (EDIBLES)". The goal of our project is to study the mysterious diffuse interstellar bands whose fingerprints are seen imprinted on stellar spectra whose lines-of-sight probe the interstellar medium. In particular the survey will measure at high accuracy the atomic and molecular content of diffuse interstellar clouds detected towards more than 150 stars. From detailed modelling we will attempt to reverse engineer physcial-chemical properties of the carriers of these unidentified absorption bands.
Cosmic Tree or Tree of Life is a common motif in various world theologies, mythologies, and philosophies. In the present study we will focus on Armenian and Iranian Cosmic Tree. In ancient Armenia, the Tree of Life (Կենաց Ծառ) is a religious symbol and is drawn on walls of fortresses and carved on the armour of warriors. According to ancient Armenians the center of the Universe is located at the crown of the tree or the column, which is the closest to the sky. We explore the idea of cosmic tree in the riddles, prayers, medieval rituals and miniatures. In the riddles the tree mostly symbolizes the celestial phenomena (Sun, Stars, and Heavens), different units of time (years, months, weeks, days, and seasons), the people, Jerusalem, the apostles and Jesus Christ.The branches of the tree were equally divided on the right and left sides of the stem, with each branch having one leaf, and one leaf on the apex of the tree. Servants stood on each side of the tree with one of their hands up as if they are taking care of the tree. In pre-Islamic Persian mythology, the Gaokerena world tree is a large, sacred Haoma tree which bears all seeds. Ahriman created a frog to invade the tree and destroy it, aiming to prevent all trees from growing on the earth. As a reaction, God (Ahura Mazda) created two kar fish staring at the frog to guard the tree. The concept of world tree in Persian Mythology is very closely related to the concept of Tree of Life. Another related issue in ancient mythology of Iran is the myth of Mashyа and Mashyane, two trees who were the ancestors of all living beings. This myth can be considered as a prototype for the creation myth where living beings are created by Gods (who have a human form). We come to the conclusion that in both cultures the perception of Cosmic Tree is interconnected to the life on our planet and served as a metaphor for common descent in the evolutionary sense.
In this work we are presented the Observations of HH 161 is carred out in Byurakan Astrophysical Observiatory using multipupil spectrograph VAGR, attached on prime focuse of the 2.6 m telescope. The integral field spectroscopy is very effective method to investigate the kinematics and physical parameters of Herbige-Haro objects. We present the results of the study of the Herbig-Haro jet - HH 161 are presented.
The results of surveys on DSS2 B, R and ESO/SRJ E, J plates are presented. During these surveys several dozens of radial systems were found. A hypothesis is suggested that the groups of semistellar starless condensations are just radial systems of dark globules situated behind thick molecular clouds.
The repeatedly discussed effect of tiny acceleration of several spacecrafts toward the Sun is considered once more. There were many attempts to find the physical mechanism causing the mentioned effect. Nevertheless, it was unknown for rather long time. Moreover, the mechanism allegedly explaining the effect was borrowed from the ones already considered and rejected earlier. On the other hand the discovery of the Universe accelerating expansion changed radically our ideas on its dynamics and showed that we live in a not inertial frame. It became evident that no any point within our Universe may be considered inertial. One should take into account that every point has some speed and some acceleration. And the only rest system available is connected with the “primeval point” – the cosmological horizon. In the mentioned system we should observe the same very tiny acceleration resembling the gravitational one at any point of the Universe. The simple calculations show that this acceleration is equal to the anomalous acceleration revealed in the motion of spacecrafts.
Instability phenomena as indicators of additional energy release had been in the focus of attention at the Byurakan observatory since the very beginning of its foundation. This approach was suggested by Viktor Ambartsumian вАУ the founder and first director of the observatory. The exceptional fruitfulness of the approach was proven many times. First of all the existence of newborn stars was proven owing to analysis of stellar association dynamics. Later on the new idea on the activity of galactic nuclei was formulated which became subsequently an important topic for extragalactic researches. This approach remains to be most important feature of astrophysical investigations at the Byurakan observatory.
Iranian National Observatory (INO) project (INO340) aims at construction of a 3.4m optical telescope currently being designed. The observatory site is located at an altitude of 3600m in central Iran mountains benefiting from very good observing conditions. The INO340 is general purpose optical telescope demanded to offer high resolution imaging over a relatively large field of view. The main mission of this telescope is optical imaging and spectroscopic follow-up observations. Given the longitude, it can be efficiently used for transient observations. INO340 is not just a telescope project but a tool to build a community of astronomers in the land of great astronomers and ancient observatories.
Fossil systems are understood to be the end product of galaxy mergers within groups and clusters. Their halo morphology points to their relaxed/virialised nature, thus allowing them to employed as observational probes for the evolution of cosmic structures, their thermodynamics and dark matter distribution. Cosmological simulations, and their underlying models, are broadly consistent with the early formation epoch for fossils. In a series of studies we have looked into the dark matter, IGM and galaxy properties, across a wide range of wavelengths, from X-ray through optical and IR to the Radio, to achieve a better understating of fossil systems, the attributed halo age, IGM heating and their AGNs and use them as laboratories to probe galaxy formation models. We combine luminosity gap with luminosity segregation to identify the most dynamically relaxed systems which allows us to reveal brand new connections between galaxies and their environments.
We present optical variability study of the 120 comparatively faint carbon (C) stars which have been discovered by searching the First Byurakan Survey (FBS) low-resolution (lr) spectral plates at high Galactic latitudes using recent wide-area variability databases.The light curves from the Catalina Sky Survey (CSS) and Northern Sky Variability Survey (NSVS) databases were exploited to study variability nature of them. From the 120 detected objects 54 are N-type Asymptotic Giant Branch (AGB) C stars.9 stars belongs to the group of Mira-type, 43 are Semi-Regular (SR), and 2 stars are Irregular (Irr)-type variables. The variability types of 27 objects has been established for the first time. K-band absolute magnitudes, distances, and height from the Galactic plane were estimated for all of the 66 objects show early – type spectra, 57 objects show spectral features which are typical of CH – giants, 4 object are classified as R – type stars.We estimate the detection range( in kpc ) for each class of carbon stars detected in the FBS. Finally, our studies of C stars found at high galactic latitude are discussed in the context of the Gaia mission.
Flare stars are one of the most studied variables. The study of these objects in Byurakan Observatory has started 50 years ago and is still one of the actual directions of investigations. During this period photographic and photoelectric monitoring, as well as polarimetric and spectral observations of flare stars in young stellar systems and the stars in solar vicinity were carried out. Colorimetric observations of stellar flares conducted simultaneously in UBV bands of spectra are especially valuable in these studies. The main results obtained from these observations are briefly presented in recent report.
A review on the activities and achievements of Armenian Astronomical Society (ArAS) and Armenian astronomy in general during the last years is given. ArAS membership, ArAS electronic newsletters (ArASNews), ArAS webpage, annual meetings, Annual Prize for Young Astronomers (Yervant Terzian Prize) and other awards, international relations, presence in international organizations, summer schools, astronomical Olympiads and other events, matters related to astronomical education, astronomical heritage, amateur astronomy, astronomy outreach and ArAS further projects are discussed.
A review on Byurakan Astrophysical Observatory (BAO) Plate Archive and Armenian Virtual Observatory (ArVO) projects is given. BAO Plate Archive consists of 37,500 photographic plates and films, obtained with 2.6m telescope, 1m and 0.5m Schmidt telescopes and other smaller ones during 1947-1991. The famous Markarian Survey (or the First Byurakan Survey, FBS) 2000 plates were digitized in 2002-2005 and the Digitized FBS (DFBS, www.aras.am/Dfbs/dfbs.html) was created. New science projects have been conducted based on this low-dispersion spectroscopic material. Several other smaller digitization projects have been carried out as well, such as part of Second Byurakan Survey (SBS) plates, photographic chain plates in Coma, where the blazar ON 231 is located and 2.6m film spectra of FBS Blue Stellar Objects. However, all other plates and films are not digitized. In 2015, we have started a project on the whole BAO Plate Archive digitization, creation of electronic database and its scientific usage. Armenian Virtual Observatory (ArVO, www.aras.am/Arvo/arvo.htm) database will accommodate all new data. The project runs in collaboration with the Armenian Institute of Informatics and Automation Problems (IIAP) and will continue during 3 years in 2015-2017. The final result will be an electronic database and online interactive sky map to be used for further research projects. ArVO will provide all standards and tools for efficient usage of the scientific output and its integration in international databases.
We have carried out a number of surveys and identification works related to X-ray, IR and radio sources and searched for extragalactic ones. Among them, most interesting are Active Galactic Nuclei (AGN) and Starburst Galaxies (SG). Some 4500 AGN have been revealed from ROSAT BSC and FSC sources, and many more are hidden ones; those showing evidence of activity but with no emission lines in optical wavelengths. IR sources contain thousands of SG, and most important are those having signs of interaction and/or merging. We have carried out optical identifications of IRAS point sources, and 1278 IR galaxies have been revealed, including LIRGs and ULIRGs. Extragalactic radio sources contain bright galaxies, AGN and SG. We have studied the border between AGN and normal galaxies by radio/optical flux ratios to establish which objects may be attributed to AGN based on radio properties. Interestingly, absolute majority of objects associated with both X-ray and radio sources are AGN.
Fossil galaxy groups have no recent major mergers in their dominant galaxies and also group scale mergers are assumed to be the last stage of galaxy formation and evolution inside the group. Study radio properties of such systems gives the opportunity to investigate the effect of galaxy merger on AGN activity in galaxy groups. In this work, we observe a sample of fossil galaxy groups in 610 MHz and 1.4 GHz using GMRT and compare the radio properties of the fossil sample with a sample of normal galaxy groups.
One of the key unsolved problems in astrophysics is to understand the formation and evolution of galaxies. There are many complementary approaches to study the evolution of galaxies and infer how distant galaxies are connected to galaxies in the present day universe. These canonical ways are either focused on the evolution of luminosity/mass function, star formation rate density, or the evolution of the observed scaling relations of galaxies. Among the scaling relations, the relation between the stellar mass and sizes of galaxies has considerable importance. Evidence is provided by many recent studies that the size of galaxies were smaller at higher redshifts compared to galaxies of similar mass in the local Universe. Studying these galaxy properties at different epochs can place important constrains on the underlying processes assumed for the galaxy mass and structural evolution. I will present the study of the mass-size evolution of galaxies from redshift z=7 to z=1 and the stellar mass-size relation for nearby galaxies (z=0). Also, I will present the stellar mass assembly history of quiescent and star-forming galaxies between z=2 and z=0.5, by studying the radial mass profile of these galaxies.
The main instrument of Byurakan Observatory is 2.6m reflector, which is fully modernized during last years and now is operational. At Prime focus of the telescope auto-guiding system is attached, which allows to obtain large exposures. The main instrument of 2.6m telescope is SCORPIO multimode camera, which can work in imagery, slit spectroscopy and slitless modes. As a detector we use Tektronix 1048x1048 blue sensitive CCD cooled with liquid nitrogen. Spectral camera is equipped with wide and narrow band filters for imagery and various resolution grisms for spectroscopy. Besides, we have multi-pupil integral field spectrograph – VAGR, which provides 40 arcsec field of view with 1 arcsec per micro-lens sampling. We use spectrograph in high resolution and low resolution modes with 2.1 A/pix and 0.5 A/pix dispersion respectively. Second large instrument is 1m Schmidt telescope equipped with 4000x4000 CCD providing about 1 degree field of view, and a set of wide and mid-band filters. This telescope is planned to be used for different wide field spectral and photometric surveys. On the other hand, we have some small telescopes: 50cm and 40cm Cassegrain and 50cm Schmidt telescopes. Some of them are equipped with CCD cameras.
Four binary objects and one triplet have been revealed in the young stellar cluster located in the vicinity of IRAS 05137+3919 source on a distance 4.4 kpc with the use of statistic analysis (2PCF, Poisson statistics). They are including the pair of Ае/Ве Herbig stars. The percentage of the multiple systems in the cluster is mf = 5 % and cp = 10 %. The mass of the multiple systems’ components are located in the range from 1 to 8 Мsol and log P (rotation period in years) - from 4.4 to 4.7. The median value of the mass ratio of the components is q=0.73. The percentage of the multiple systems and their parameters in this cluster is resembling with the data obtained in the other star forming regions (ONC, Perseus, U Sco A), in which the values of mf and cp parameters are comparable with the results obtained for field’s stellar population.
Since one decade, the gravitational microlensing became one of the important methods for exploring the extra-solar planets. I will review the physics of this method and recent discoveries in this field. The future prospects of using microlensing for the stellar studies also will be discussed in this talk.
We study the local and global stability of self-gravitating disks in the context of modified gravity (MOG). MOG is a covariant generalization of general relativity. This theory is an alternative for dark matter particles. On the other hand the stability of spiral galaxies is directly linked to the dark matter problem. Thus it seems necessary to check the astrophysical consequences of MOG in the issue of gravitational stability. More specifically, we derive the generalized version of the Toomre's criterion and present some N body simulation for the global stability of spiral galaxies.
AGN, their evolution and their relativistic jets were studied on the basis of data from multi-wavelength surveys. NRAO VLA Sky Survey (NVSS) were used to study radio jets and radio continuum emission of AGN. The properties of selected objects were collected from IR catalogs of 2MASS and WISE as well FBS surveys at CDS and X-Ray surveys of Chandra, XMM-Newton, and NuSTAR. Through this study the objects were classified due to their redshifts to study the properties of their relativestic jets at low and high redshifts.
The sample of ~390 galaxies is presented that have mid-infrared, high resolution spectroscopy with the Spitzer Infrared Spectrograph (IRS) and also spectroscopy of the [CII] 158 µm line with the Herschel Photodetector Array Camera and Spectrometer. The emission line profiles of [NeII] 12.81 µm and [NeIII] 15.55 µm are analyzed for future comparison to the [CII] line profiles. Alternative IRS spectral extractions recently made available in the Cornell Atlas of Spitzer/IRS Spectra (CASSIS) are used to determine empirical uncertainties, and instrumental resolution of the IRS is measured using planetary nebulae. It is found that line widths (defined as full width half maximum of Gaussian profiles) have median values of 399km s^{-1} for the [NeII] line, which is the line that arises primarily in starbursts that also produce [CII] emission. Galaxies are classified using the strength of the polycyclic aromatic hydrocarbon 6.2 µm feature, and active galactic nuclei have median [NeII] line widths of 399km s^{-1} compared to 303km s^{-1} for starbursts.For my objectives, the most important question for now is whether the Neon line widths are affected by the presence of an AGN. Previous studies have measured the mid-infrared line widths only in AGN, so it is important to determine if these systematically differ for starbursts.
Through multi-wavelength flux ratios it is possible to detect AGN and Star-burst. Techniques of detecting extragalactic objects as well as AGN is studied in different wavelengths (X-Ray, Radio and IR). Specification of AGN as IR and radio sources is discussed. IR catalogs of 2MASS and WISE were used to study the interrelationship between interactions/merging, starburst and AGN phenomena. To classify the properties of AGN, FBS surveys at CDS and X-Ray surveys of Chandra, XMM-Newton, and NuSTAR were used. A cross correlation between some specifications of AGN and their total and maximum fluxes at different wavelengths is made and the IR ones were discussed in more details.
The Interface Region Imaging Spectrograph (IRIS) of the recently commissioned NASA small explorer mission provides significantly more complete and higher resolution spectral coverage of the dynamical conditions inside the chromosphere and transition region (TR) than has heretofore been available. Near the solar limb high temporal, spatial (0.3'') and spectral resolution observations from the ultraviolet IRIS spectra reveal high-energy limb event brightenings (LEBs) at low chromospheric heights, around 1 Mm above the limb. They can be characterized as explosive events producing jets. We selected two events showing spectra of a confined eruption just off or near the quiet Sun limb, the jet part showing obvious moving material with short duration large Doppler shifts in three directions identified as macrospicules on slit-jaw (SJ) images in SiIV and HeII 304 Å. The events are analyzed from a sequence of very close rasters taken near the central meridian and the South Pole limb. The processed SJ images and the simultaneously observed fast spectral sequences having large Doppler shifts, with a pair of red shifted elements together with a faster blue shifted element from almost the same position, are analyzed. Shifts correspond to velocities of up to 100 km/s in projection on the plane of the sky. The occurrence of erupting spicules and macrospicules from these regions is noticed from images taken before and after the spectra. The cool low first ionization potential (FIP) element simultaneous line emissions of the MgII h and k resonance lines do not clearly show a similar signature due to optical thickness effects but the SiIV broad-band SJ images do. The bidirectional plasma jets ejected from a small reconnection site are interpreted as the result of coronal loop-loop interactions leading to reconnection in nearby sites.
Astronomy in Georgia is generaly represented in Abastumani Astrophysical Observatory which was found in 1932. It is one of the leading scientific institutes in the country. Several telecsopes are operational today, as well as the instruments for atsmopheric studies. Main fields of research are solar system bodies (including near-Earth asteroids), various aspects of solar physics, stellar astronomy (including binary stars and open clusters), extragalactic objects (AGNs), theoretical astrophysics, cosmology, astmospheric and near space physics. In 2007 the Observatory was integrated in Ilia State University, merging scinetific research and education which facilitated the growth of a new generation of Georgian astronomers. There are groups of astronomers and astrophysicists in other universities and institutions as well. Georgian scientists collaborate with many research centers and universities worldwide, including Byurakan Astrophysical Observatory. Research groups participate in various international astronomical projects. The interest in astronomy in Georgia has been rising, which increases future perspectives of its development in the country.
Investigation of the influence of cosmic factors (i.e. galactic cosmic rays, solar wind, etc.) on the Earths's atmosphere is an important issue in the atmospheric and solar-terrestrial coupling studies. Contribution of cosmic factor to the climate change, which is included in the solar-terrestrial coupling models, is still unknown. We studied long-term inter-annual variations of cloud covering in Abastumani Astrophysical Observatory (41.75N, 42.82E) during day- and night-time, at various helio-geophysical conditions, as well as coupling with cosmic factors. We found that these distributions are different: for cloudless days they have annual periodisity, while for cloudless days they are coth annual and semi-annual, depending also on geomagnetic activity. This may be a manifestation of possible influence of cosmic factors on cloud covering.
The research was supported by Shota Rustaveli National Foundation Grant No 31/81.
In this work there are presented the results of the statistical analysis of the ∼200 stars with Нα emission in the IC 348 cluster. The sample includes stars with R > 20.0 magnitudes. The optical radius is ∼11'. The percentage of emission stars increases from bright to faint objects and to the range of 13.0 ≤ R-AR ≤ 19.0 reaches 80%. The ratio between WTTau and CTTau objects is 64% and 36%. The 70% of X-ray sources are WTTau stars. The WTTau and CTTau objects have similar ages about 2•106 years. The non-emission stars with the mass less than the solar mass have ∼2•106 years ages also, but non-emission more massive objects are "older". The age of the massive objects is ∼7•106 years. The most massive stars with a low level of activity are concentrated in a small dense central core of the cluster with a radius ∼1'.Apparently, they are generated during an early stage of star formation..
Presented are the results of a statistical study of galaxies with UV excess from six Kazarian lists. Morphology, activity, heliocentric redshift and the magnitude of 502 out of 702 galaxies from Kaziarian lists were considered. It is shown that these galaxies have different morphological types, different degrees of activity, and often contain condensations and double nuclei. It is also shown that most of the closely located Kazarian galaxies form physical systems.
Complex chemical species are easier formed in a solid phase, for example in a mixture of ices of water, carbon oxides, methane, ammonia, methanole and other, less abundant molecules. Ultraviolet photons in the range 5-13.6 eV and the charged particles with MeV-GeV energies serve as an energy source of reactions. Icy particles containing mentioned substances, can exist only in internal areas of the interstellar molecular clouds protected from influence of external ultraviolet radiation. However cosmic rays are capable to penetrate in clouds and to cause an irradiation of ices by means of secondary ultra-violet photons necessary for initiation of chemical reactions of complexisation. In this work doses of irradiation of ices are calculated when fluxes of cosmic rays on 3-4 order exceed modern values in the Galactic disk. Such fluxes are inherent in active galaxies with cosmic ray dominated regions. Results of presented calculations show that originated complex species may get overdoses and be carbonizated under such conditions.