Optical identifications of a few thousands of IRAS sources showed that IRAS Point Source and IRAS Faint Source catalogues (PSC and FSC, respectively) contain many quasars and active galactic nuclei, late-type stars, planetary nebulae, variables, etc. To increase the efficiency of using IRAS PSC and FSC, which contain a lot of common sources, one needs a joint catalogue of all IRAS point sources with improved data based on both catalogues. However, cross-correlation of the catalogues is not so easy, as the association of many sources is relative, and not always it is obvious, whose source from one catalogue corresponds to the other one in the second catalogue. This problem exists in case of using standard cross-correlation tools. Therefore, we have created a tool for cross-matching astronomical catalogues and we have applied it to IRAS PSC and FSC. Using this tool we have carried out identifications with a search radius corresponding to 3-σ of errors for each source individually rather than a standard radius for all sources. As a result, we obtained 73,770 associations. In addition, we have made cross-correlations with AKARI-IRC, AKARI-FIS and WISE catalogues. We created a catalogue of 345,163 IRAS sources with high positional accuracy and with 17 photometric measurements from 1.25 to 160 um range, providing a detailed catalogue for IRAS point sources. We gave 2 types for all sources: galaxy and star. In this catalog we have 145902 galaxies (42 %). In this work we investigation this galaxies and we can understand some properties of IRAS PSC/FSC galaxies.
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 of 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 Galaxy 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 have elaborated a set of new algorithms and programs for advanced time series analysis of (generally) multi-component multi-channel observations with irregularly spaced times of observations, which is a common case for large photometric surveys. Previous self- review on these methods for periodogram, scalegram, wavelet, autocorrelation analysis as well as on “running” or “sub-interval” local approximations were self-reviewed in (2003ASPC..292..391A). For an approximation of the phase light curves of nearly-periodic pulsating stars, we use a Trigonometric Polynomial (TP) fit of the statistically optimal degree and initial period improvement using differential corrections (1994OAP.....7...49A). For the determination of parameters of ”characteristic points” (minima, maxima, crossings of some constant value etc.) we use a set of methods self-reviewed in 2005ASPC..335...37A, Results of the analysis of the catalogs compiled using these programs are presented in 2014AASP....4....3A. For more complicated signals, we use ”phenomenological approximations” with “special shapes” based on functions defined on sub-intervals rather on the complete interval. E.g. for the Algol-type stars we developed the NAV (“New Algol Variable”) algorithm (2012Ap.....55..536A, 2012arXiv1212.6707A, 2015JASS...32..127A), which was compared to common methods of Trigonometric Polynomial Fit (TP) or local Algebraic Polynomial (A) fit of a fixed or (alternately) statistically optimal degree. The method allows determine the minimal set of parameters required for the “General Catalogue of Variable Stars”, as well as an extended set of phenomenological and astrophysical parameters which may be used for the classification. Totally more that 1900 variable stars were studied in our group using these methods in a frame of the “Inter-Longitude Astronomy” campaign (2010OAP....23....8A) and the “Ukrainian Virtual Observatory” project (2012KPCB...28...85V).
ESA’s Gaia mission will survey the sky for at least 5 years measuring high accuracy astrometry, radial velocities and multi-colour photometry. The Data Analysis and Processing Consortium (DPAC) efforts will result in an astronomical catalogue with unprecedented accuracy and completeness of up to 1 billion (1E9) sources, and over 1PB of associated data products. This brings big data challenges in storing, querying and distributing all the associated data and metadata, comparing them with other astronomical catalogues, enabling analysis, visualization, data mining and then sharing these results with other scientists. The amount of data involved forces a change of paradigm in dealing with astronomy archives. The usual usage of downloading the data to the users for her/him to work further on it needs towards evolve to a new way of working where the users’ can send her/his code to the data, run it there on computing and storage services provided directly by the archive, where the data reside. To answer to all these new technical challenges, the Gaia Archive has directly adopted VO standards (TAP, ADQL, UWS, VOSpace, SAMP amongst others) to build the archive data management infrastructure, giving birth to one of the first “VO-built in” astronomy archive. Embracing VO technology from the start also ensures full interoperability of the Gaia archive to other VO compliant data archives and applications.
The main aim of the presentation is to introduce the current needs of Astro community from the Computational Science and "Big Data", which are already the "third" and "forth" pillars of science. In addition it will be presented the facilities available in Armenia and activities that are planned.
The sample of nearby active galaxies of the SBS is studied. It limited from z < 0,01 and consists from 130 galaxies. As a rule it is the dwarf galaxies, usually its diameter doesn’t exceed 10 kpc. The morphology of active regions in these galaxies and galaxies themselves investigated on the SDSS images. It is shown that 10 active galaxies really are the giant HII regions in the galaxies. These galaxies may be active or not. Special cases are the comet-like galaxies. They were exceeded by Markarian as one morphological type of the UV galaxies. Now they have and other name – tadpoles. The diagramme (g-r) vs (u-g) is created. The u, g, r Petrosian’s magnitudes is used. Tadpole galaxies occupy special position and easily separate from the most galaxies of other types. But and some other galaxies fall in this region. The consideration is shown that this is small blue galaxies with the asymmetric active region. Probable among these there are some tadpole galaxies which inclined to the line of sight under different angles.
30 spectroscopic binary stars were found in the SBS Survey. They show composite spectra - WD(DA)+dM или dC (for example Liebert et all, 1994). They may have red colour, if the radiation of the red star dominates, blue one, if the blue star is brighter and have pecular spectrum on our survey plate. We obtained slit spectra for the most of such objects. But we often seen the spectrum from one component, because our slit spectra didn’t cover all optical range. Well, we seen by eye the slit spectra of all stellar SBS objects (~700) in SDSS789 in spite that we observed or not this object. So we confirmed or discovered the duplicate of 30 stars. Usually there are the spectroscopic binaries, where the one component is the WD (DA) and second red star with emission or not. There are and other components combinations. Sometimes emission line, probably, variable. In the list we included only one object SBS1040+493, which is the binary star with ρ~8″. We obtained the slit spectrum of the WD, and slit spectrum of the red star was received in SDSS. The wide pair with ρ>10″ we excluded from consideration. So slit spectra were received either survey authors or taken from SDSS789. It is shown, that 10% SBS WD are the binaries.
Revised and updated new version SBS Catalogue was presented. It includes ~3600 stellar and diffuse objects from witch ~600 QSOs, ~170 Sy-type galaxies and 12 BLL. Survey is not finished and in Catalogue are 430 ″unobserved″ or ″unclas″ objects. Usually we observed ″unclas″ objects, but received uncertain or incomplete data, or data taken from literature. For ″unobserved″ objects we up to now haven’t slit spectra and physical classification is impossible. The comparison the catalogue data with SDSS9 was done. The accuracy determination of redshifts and physical classifications according the comparison the objects with these two lists was presented - 1383 objects. The rough errors in redshifts and classification were corrected. It is shown that 30-40 stellar “unobserved” objects may be QSOs. The multiwavelength data from other diapasons spectra was compiled.
The CALIFA survey is a project designed to observe a statistically well-defined sample of ~600 galaxies in the local universe using 250 observing nights with the PMAS/PPAK integral field spectrophotometer, mounted on the Calar Alto 3.5m telescope. PPAK offers a combination of extremely wide field-of-view (>1 arcmin2), good spectral resolution, and wavelength sensitivity across the optical spectrum. The spectra cover the range 3700-7000A in two overlapping setups, one in the red (4300-7000A) at a spectral resolution of R~850 and one in the blue (3700--5000A) at R~1650. The survey aims at addressing some of the most fundamental issues in galaxy evolution: 1) extend the kinematic classification of galaxies over the whole Hubble sequence, 2) study the ISM over entire galaxies (e.g. the importance of AGN, star formation, shocks and old stars as ionization sources), 3) derive stellar population gradients in age and metallicity to constrain the formation mechanisms of early-and late-type galaxies alike. The survey has already produced its second data release, delivering high-quality datacubes for 200 galaxies in the two instrumental setups (http://califa.caha.es/DR2). In this presentation I will give an overview of the current status of the survey and summarize some of the latest results from the analysis of the stellar kinematics, ionised-gas emission and stellar populations in our sample of nearby galaxies.
The goal of this study is to develop a tool for detection of errors and misprints in principal catalogues of visual binary stars. Modern statistical investigations of visual binaries (which are about 130 thousand, and they represent the most numerous observational type of binaries) are based almost exclusively on data, listed in those catalogues. So their correction is a challenging task, otherwise the statistics of visual binaries can be biased. Study of individual stars should also based on correct data. We have presented tools to detect some of errors in the catalogues, particularly, to indicate cases (i) when a binary or a component is included in a catalogue twice, under different names, and (ii) when positional information on a concerned (secondary) component in a pair is contradictory. Altogether 13118 erroneous entries are detected in the studied catalogues.
The Goal of Our work is to present and analyse a new sample of cool carbon( C ) stars located in the Galactic Halo. These rare objects are discovered by searching the 2MASS point-source catalogue for candidates having near-infrared colours typical of C stars. Optical spectroscopy is subsequently performed. The number of 2MASS selected Halo C stars is now 150. We first present a few new discoveries of C stars in Fornax. We compared the halo results to C star populations in the Fornax dwarf spheroidal galaxy, Sgr, and the solar neighbourhood. The narrow location in the JHK diagram of the Halo C stars is found to differ from that of similar C stars in the above galaxies. The light curves of the Catalina and LINEAR variability database were exploited to derive pulsation periods of Halo C stars. We confirm that the period distribution of the Halo strongly resembles that of Fornax, and we found it is very different from the C stars in the solar neighbourhood. There is a large proportion of short-period Mira/SRa variables in the Halo than in Sgr, but the survey for C stars in this dwarf galaxy is not complete, and study of their variability needs to be continued to investigate the link between Sgr and the cool Halo C stars.
A survey of radial systems of dark globules was taken place. This survey was done both in Northern Hemisphere (on DSS2 R and B plates) and in Southern Hemisphere (on ESO/SRJ R, J and B plates). During these surveys several dozens of new radial systems were obtained. It is possible to divide these systems in two types. 1.Systems with central early type bright stars, HII regions and radial systems of dark globules. 2.Systems without central bright stars and without HII regions, but with radial systems of dark globules.
A comprehensive phased investigation was undertaken for the sample initially formed from about 500 objects, selected as candidates for active galaxies in seven fields of the Second Byurakan Survey. Based on completed in the first stage follow-up spectroscopy, the redshift survey and preliminary classification of activity were done. Investigations of individual objects based on panoramic spectroscopy are the current stage. Statistics and the details will be presented.
Images in the balmer Hɑ line of hydrogen and other data on some Markarian galaxies, obtained from panoramic spectroscopy, are presented. Observations were carried out using the multipupil spectrographs MPFS and VAGR at the 6-m telescope of SAO of RAS and the 2.6-m BAO of NAS RA, correspondingly. In case of MPFS we have spectral ranges of about 1000Å, with the centers close to position of the object's Hɑ. So that, except the mapping of Hɑ emission, assigned as main task, data on forbidden lines, at least [NII]6548,6583, are available as well. Spectrograph VAGR, which has advantage in angular size of the field of view, 35"x35'' instead 16"x 16'' from MPFS, was used mainly to observe more extended galaxies with Ha in the frames 6400-6800 ÅÅ, which is the spectral range of the interference filter, used with this spectrograph.
All the activity phenomena observed in cosmic objects of various hierarchical levels are united by one physical feature - they all show the release of excessive energy. As the decay of elementary particles and radioactive nuclei, and the different types of activity in the planets and stars, gigantic explosions in the galaxies may be considered as links in a long chain. It should be clearly understood that the active phenomenon differ from other types of energy release sincet the activity of an object is its intrinsic property. Then all the physical information related to these phenomena can be considered as a big data where the activity phenomena are the objects of interest. Like the “ordinary” cosmic objects the activity phenomena could be catalogued. The type of an object – the host of the given phenomenon will appear among the other characterizing parameters or values in such a catalogue. Only when at least all the known phenomena are catalogued properly and the primary regularities and correlations are revealed one can try to find the real source of energy accompanying such processes.
On the Internet there are no astronomical catalogs, related to historical period "before telescope". We present Russian online database (web-site), intended to solve this problem. The database includes the catalog of Ptolemy's "Almagest" and catalogs of al-Sufi, Khayyam, al-Tusi, and Ulughbeg. The DB based on VizieR's archive and off-line publications. Besides the astrometric data (ecliptic coordinates and magnitude of the stars) the catalogs includes original descriptions of the stars and, in some cases, original names of the stars. This is the subject of interest for the history of astronomy. Database has a user-friendly interface, catalogs are presented in human-readable form and illustrated by the interactive map. Also interface provides separate or integrated view of catalogs. The key catalog is the Ptolemy's catalog of "Almagest", since the other catalogs based on it. As the original of Ptolemy's text lost, there are many handwritten copies containing the alternative versions and slips. The observational data also contains systematic errors of various kinds. That's why a reliable identification of the stars in the catalog of "Almagest" is as important, as difficult. Three available publications of Ptolemy's catalog were compared, and their identifications in concordance with Yale Bright Star Catalogue was analyzed. The verification by photocopies was used as necessary. The mechanism of visual control identification by Lite Aladin applied; also "Almagest" text analysis was used to identification in cases of dispute. While comparing of the sources, there were found different variants of identifications and errors of identification. Different variants of identifications were ranked in terms of reliability, errors corrected if possible. For other catalogs sources were verified and cross-identificated with the "Almagest" catalog.
The electron and proton trajectories in water are calculated by solving a set of coupled stochastic differential equations. The energy range for an electron is considered in no screening region in order to calculate the folding theory analytically. In this case, the projectile velocity does not change in each interval. On the other hand, the projectile loses energy by collision and then by radiation. To satisfy this method with experimental data, the probability density function (PDF) of energy as well as the dose deposition for an electron and proton beam in water and aluminum are calculated. The results obtained in our analysis are in good agreement with experimental data reported in the literature.
The Armenian Virtual Observatory is a platform to tackle with the astronomical data and provide services based on the standards developed by IVOA. The main aim of the article to introduce not only ArVO data services, which enables to manage different data resources and provide the uniform data access interface for users, but also web services for cross matching and spectra extraction. Special attention is paid to the data sharing and collaboration with the international astrophysical databases.
The central regions of Active Galactic Nuclei (AGN) are believed to have a rich and complex structure, but unfortunately they are unresolved points, and are likely to remain so. One of the few possibilities for decoding their structure is by the study of their variability at different wavelengths and timescales. Repeated massive surveys are opening up exciting new possibilities - firstly, by finding and studying the rarest objects, such as tidal disruption events and microlensed AGN - and secondly by compiling the population properties, and finding dependences on type, luminosity, black hole mass, redshift, and so on. I will look at recent results and future prospects.
The methods of searches and catalogization of Herbig-Haro objects are described, starting from the early period up to the present situation. Further prospects and the necessities of the search continuation are discussed.
Binary star DataBase (BDB) is the world's principal database of binary and multiple systems. BDB is created as a source joining the comprehensive information on binary stars of all observational and evolutionary types. BDB contains data on physical, photometric, spectroscopic, orbital and positional parameters of 240000 components of 110000 stellar systems of multiplicity 2 to more than 20, taken from a large variety of published catalogues and databases. Organization of the information is based on the careful cross-identification of the objects. BDB can be accessed interactively at http://bdb.inasan.ru via a web-interface. BDB data can be queried using two methods: by identifier and by parameters. BDB is useful for investigation of a number of scientific problems, such as statistical study of the binary stars population in the Galaxy, determination of the masses and other physical parameters of the stars, study of binary evolutionary scenarios, etc. BDB can also be useful for observations planning.
The search and the study of emission objects in dark cloud regions have started since 1979. More than 15 regions have been selected from the Havtassy dark clouds for observations. Observations of these regions were carried out with 40вАЭ Shchmidt telescope of BAO in 1979, 1985 and 1989. The 4o objective prism was used during the observations. Preliminary results of 6 regions allowed to detect more than 200 new emission stars in a area of about100sq.deg. More than 10% of emission stars have shown variations of Ha intensity. In some selected regions with a total area of about 0.5sq.deg. the search and the study of emission objects have been done with 2.6m telescope of BAO. More than 100 new emission objects were detected in these regions. The main results obtained from these observations are presented.
Byurakan Astrophysical Observatory (BAO) has always been one of the centres for surveys and studies of active galaxies. Our projects since late 1980s are focused on multiwavelength search and studies. 1103 blue stellar objects (BSOs) on the basis of their UV-excess were selected using Markarian Survey (First Byurakan Survey, FBS) plates and Markarian’s criteria used for the galaxies. Among many blue stars, QSOs and Seyfert galaxies were found by follow-up observations. 1577 IRAS point sources were optically identified using FBS low-dispersion spectra and many AGN, Starbursts (SB) and high-luminosity IR galaxies (LIRG/ULIRG) were discovered. ROSAT FSC sources were optically identified using Hamburg Quasar Survey (HQS) low-dispersion spectra and many AGN were discovered by follow-up observations. Fine analysis of emission line spectra was carried out using spectral line decomposition software to establish true profiles and calculate physical parameters for the emitting regions, as well as to study the spectral variability of these objects. X-ray and radio selection criteria were used to find new AGN and variable objects for further studies. Multiwavelength approach allowed revealing many new AGN and SB and obtaining a number of interesting relations using their observational characteristics and physical properties.
A review of astronomical surveys (especially all-sky and large area ones), catalogues, databases and multiwavelength archives is given. Recent large astronomical surveys and resulting catalogues during the last 15 years accumulated vast amounts of data over the whole range of electromagnetic spectrum from γ-ray to radio. All-sky and large area astronomical surveys and catalogues include Fermi-GLAST (Acero et al. 2015) and INTEGRAL (Bird et al. 2010) in γ-ray, ROSAT (Voges et al. 1999; 2000) in X-ray, GALEX (Bianchi et al. 2011) in UV, SDSS (Alam et al. 2015) and several POSS1/2 based catalogs (APM, MAPS, USNO, and GSC) in optical range, 2MASS (Cutri et al. 2003; Skrutskie et al. 2006) and WISE (Cutri et al. 2013) in near and mid infrared (NIR/MIR), IRAS (IRAS 1988; Moshir et al. 1990) and AKARI (Ishihara et al. 2010; Yamamura et al. 2010) in mid and far infrared (MIR/FIR), NVSS (Condon et al. 1998) and FIRST (Helfand et al. 2015) in radio and many others, as well as most important surveys giving optical images (DSS, SDSS), variability (GCVS, NSVS, ASAS, Catalina) and spectroscopic (FBS, SBS, Case, HQS, HES, SDSS, CALIFA, GAMA) data. Future huge projects are expected, such as Gaia Space Observatory survey of our Galaxy and LSST wide-field telescope sky survey. Overall understanding of coverage along the whole wavelength range and comparisons between various surveys are given: galaxy redshift surveys, QSOs, radio, Galactic structure, and Dark Energy surveys. Present astronomical archives and databases contain billions of objects, both Galactic and extragalactic, and the vast amount of data on them allow new studies and discoveries. A review of most important archives and databases is also given. Astrophysical Virtual Observatories (VO) use available databases and current observing material as a collection of interoperating data archives and software tools to form a research environment in which complex research programs can be conducted.
Byurakan Astrophysical Observatory (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. In 2015, we have started a project on the whole BAO Plate Archive digitization, creation of electronic database and its scientific usage. A Science Program Board consisting of BAO experienced observers is created to evaluate the observing material, to investigate new possibilities and to propose new projects based on the combined usage of these observations together with other world databases. The Executing Team consists of 10 astronomers and 2 computer scientists and uses 2 EPSON Perfection V750 Pro scanners for the digitization, as well as Armenian Virtual Observatory (ArVO, www.aras.am/Arvo/arvo.htm) database to 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.
One of the most prominent features of young stellar objects in the optical range is the presence of emission lines, in particular Hα at 6563Å. Therefore, Hα emission detection is the most common spectroscopic means for identifying young stars. We present the search's results of PMS stellar objects in several star forming regions carried out on 2.6 m telescope in Byurakan observatory. We have used the method of slitless spectroscopy employing a grism in combination with a narrow-band Hα interference filter to detect the objects with Hα emissions.
The spectrophotometric characterization of IR sources is essential for studying the evolution of late type stars: the observed colors and spectral features of cool stars become constraints for modeling the behavior of these objects. A large number of entries in IRAS Point Source Catalog are not associated with objects in any available catalog or have only approximate classication. Through a reliable analysis and interpretation of newly obtained and literature data, we aimed at clarifying the nature of poorly investigated IRAS point sources classied as late type stars, and at contributing to the knowledge of the intermediate Galactic latitude regions. For a number of stars belonging to Byurakan IRAS Stars (BIS) catalog, we performed medium resolution spectroscopy to improve the spectral classication, previously based on optical color indices and/or on very low resolution spectra. We have collected photometric data from literature and made new photometric observations to study the variability. We also analyzed the distribution of our stars in several color-color IR plots. We assigned or revised the variability class of our targets (regular variable, semiregular, non variable) and we could locate each group in several color-color IR diagrams; the few discrepant cases can be most probably ascribed to the uncertain magnitudes reported in the catalogs. We revised the spectral types and determined distances and physical properties, like absolute magnitudes and mass loss rates. The distances of our stars range between 1.3 and 10 kpc, with a median distance from the galactic plane of 2.8 kpc, indicating that they mostly belong to the thick disk population. The spectra showed that 4 out of 37 stars are N carbon stars in the Asymptotic Giant Branch, the others being M-type stars. The color-color diagrams indicate that there are no dwarfs in our sample but only late-type
giants. The color-color plots involving the WISE colors are the best to characterize the variability behavior and to distinguish the carbons from the other stars of the sample.
The availability of infrared spectroscopic archives from the Spitzer Space Telescope make possible new, crucial, and unique observational studies of dusty galaxies. To assure easy access to the best possible spectra from the Spitzer Infrared Spectrograph (IRS; Houck et al. 2004), CASSIS team have already developed the Cornell Atlas of Spitzer IRS Sources (CASSIS) found at cassis.astro.cornell.edu or cassis.sirtf.com. At present, all low resolution (Lebouteiller et al. 2011) and high resolution (Lebouteiller et al. 2015) staring observations with the IRS are available (more than 20,000 spectra of about 15,000 distinct sources). Spectra are provided in various formats to enable easy viewing or measurements. Spectra cover 5 μm to 37 μm in low resolution (R ∼ 60 or 125) and 10 μm to 37 μm in high resolution (R 600) modes. CASSIS is intended as a long term resource for the astronomical community so that this fundamental data base of mid-infrared spectra will be easily usable perpetually.
The IPDA's main emphasis is to ease discovery, access and use of planetary data by world-wide scientists regardless of which agency is collecting and distributing the data. Ensuring proper capture, accessibility and availability of the data is the task of the individual space agencies. The IPDA is focusing on developing an international standard which allows the following capabilities: query, access and usage of data across international planetary data archive systems. While, trends in other areas of space science are concentrating on the sharing of science data from diverse standards and collection methods, the IPDA shall concentrate on promoting standards which drive common methods for collecting and describing planetary science data across the international community. Such an approach will better support the long term goal of easing data sharing across system and agency boundaries. An initial starting point for developing such a standard will be internationalization of NASA's Planetary Data System standards.
Well-designed astronomical surveys are powerful and have consistently been keystones of scientific progress. The Byurakan Surveys using a Schmidt telescope with an objective prism produced a list of about 3000 UV-excess Markarian galaxies but these objects have stimulated an enormous amount of further study and appear in over 16,000 publications. The CFHT Legacy Surveys used a wide-field imager to cover thousands of square degrees and those surveys are mentioned in over 1100 publications since 2002. Both ground and space-based astronomy have been increasing their investments in survey work. Survey instrumentation strives toward fair samples and large sky coverage and therefore strives to produce massive datasets. Thus we are faced with the “big data” problem in astronomy. Survey datasets require specialized approaches to data management. Big data places additional challenging requirements for data management. If the term “big data” is defined as data collections that are too large to move then there are profound implications for the infrastructure that supports big data science. The current model of data centres is obsolete. In the era of big data the central problem is how to create architectures that effectively manage the relationship between data collections, networks, processing capabilities, and software, given the science requirements of the projects that need to be executed. A stand alone data silo cannot support big data science. I’ll describe the current efforts of the Canadian community to deal with this situation and our successes and failures. I’ll talk about how we are planning in the next decade to try to create a workable and adaptable solution to support big data science.
Georgian, Persian, and Arabic astronomical manuscripts of period 9-19 centuries are kept in various centers, archives, and libraries of Georgia. We prepared and published unique database Astronomical manuscripts in Georgia. DVD database has been published by Ilia State University Press. It contains descriptions of Georgian, Persian, and Arabic astronomical manuscripts in form of treaties, calendars, star catalogs, and etc. The database contains as well descriptions of translated materials from Byzantine and Armenian sources. The present paper is dedicated to description of our results and presentation of DVD database.
Thanks to the rapid advances in robotic telescopes and wide field surveys, the time domain astronomy leads to a large number of transient events detected in images every night. Data mining and machine learning tools used for object classification are presented. The goal is to automatically classify transient events for both further follow-up observation by a larger telescope and for statistical studies of the transients. A special attention is brought to the identification of gamma-ray burst afterglows.
An astronomical survey is commonly understood as a mapping of a large region of the sky, either photometrically (possibly in various filters/frequencies) or spectroscopically. Often, catalogs of objects are produced/provided as the main product or by-product. However, with the advent of large CCD cameras and dedicated telescopes with wide-field imaging capabilities, it became possible in the early 1990s, to map the same region of the sky over and over again. In principle, such data sets could be combined to get very deep stacked images of the regions of interest. However, I will report on a completely different use of such repeated maps: namely exploring the time domain for particular kinds of stellar variability, namely microlens-induced magnifications in search of exoplanets. Such a survey was originally proposed by Bohdan Paczynski in 1986, and only a few years later three teams started this endeavour. I will report on the history and current state of these microlensing surveys: By now, routinely 100 million stars in the Galactic Bulge are monitored a few times per week. All stars with „constant“ apparent brightness and those following known variability patterns are filtered out in order to detect the roughly 2000 microlensing events per year that are produced by stellar lenses. These events are identified "online" while still in their early phase and then monitored with much higher cadence by so-called „follow-up“ networks. The most interesting of such events are those produced by a star-plus-planet lens. By now of order 50 exoplanets have been discovered by these microlensing surveys. Microlensing is complementary to other planet search techniques. Its advantages are its sensitivity to Earth-mass planets and lower, and its potential to determine the abundance of planets in the Milky Way. Recent results are being discussed which show that on average every Milky Way star has at least one planet of Neptune mass or higher.
A quartet of galaxies NGC 7769, 7770, 7771 and 7771A is a system with a complex interaction galaxies. We performed narrow-band imaging of the system in Hα+[NII] line and studied velocity field of NGC 7769. Close interaction between galaxies caused characteristic morphological features: tidal arms and bars, as well as induced star formation. Profiles of surface brightness of NGC 7769 have a characteristic break, and profiles of color indices have a minimum,caused by star formation induced by the interaction with NGC 7771. The location of SN 2003hg is also analyzed.
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 a survivability of ices under harsh conditions of active galaxies is discussed. Preliminary model calculations show that should be an anti-correlation between the cosmic ray induced ionization rate and the abundance of ices in active galaxies.