Astronomyis oldest of the natural science that comprising to the early human ancestors,Astronomy, celestial mechanics and the study of universe beyond the Earth’satmosphere is that Astrophysics.
Astronomy is easy to understand how thesethousands of lights in the sky have affected people throughout the ages. Amongthem modern astronomy is the fundamental science, motivated mainly by man’scuriosity, his wish to know more about the nature and universe. Astronomy can be divided into different branches inseveral ways of research, spherical or positional. Astronomy studies theco-ordinate system on the celestial sphere, their changes and the apparentplaces of celestial bodies in the sky.
Celestial mechanics study the movementof bodies in solar system, in stellar system and among the cluster of galaxiesand galaxies. It can be divided into different areas like as radio waves, infrared, ultra violet, X-ray, gamma raywhich has depends upon wavelength of electromagnetic spectrum are used inobservations. For the solar system is governed by the sun which produces energyin its centre by nuclear fusion. The sun is our nearest star and its studylends insight into conditions on other stars.
1 1.1 InfraredAstronomy InfraredAstronomy is the detection and study of the infrared radiation (heat energy)emitted from object in the universe .Infrared Astronomy was introduced inHungary byLajosG.
Balazs in the 1980s when he to analyze and interpret IRAS datathe Konkoly observatory Budapest 2. All object emit infrared radiation, soinfrared Astronomy involves the study of just about everything in theuniverse.In the field of Astronomy,the infrared region lies within the range of sensitivity of infrared detectors,which is between wavelength of about 1 and 300 microns. The living beings(mostly human) eye detects only 1% of light at 0.69 microns and 0.01% at 0.75microns which is very effectively, we cannot see wavelength because the lightsource is very bright.Infrared is divided into three parts i.
e. near, mid and far infrared. Near infrared refers to thepart of the infrared spectrum that is closest . Figure1:Visible (courtesy of Howard Macallon), nearinfrared(2mass) and mid infrared(ISO) view of the Horse head Nebula ,imageassembled by Robert Hurt. 3to visible light and far – infraredrefers to the part that is closer to the microwave region.
Mid-infrared is theregion between these two.Infrared Astronomy has been greatsignificance to peer through the veil of interstellar dust, which blocks lightin the visible wave length of the electromagnetic spectrum. It is able to dothis that’s why light in the infrared region pass right through interstellardust, completely unaffected, thus enabling us to see objects whose light wouldnormally be blocked from our view, and again enables us to see at extremecosmological distances that is galaxies in the early universe, the light ofwhich is so red- shifted that they are visible in the infrared only.4 2.
Literature Review 2.1 FlarestarAvariable star which has unpredictably have a massive increases in itsbrightness across the electromagnetic spectrum for a few minutes and similar tothe solar flares, they are magnetic disturbances in the atmosphere of stars.The brightness increases across the spectrum from x-ray to radio waves.Thefirst known discovered flare is V1396 CYgni and at microscopic but the bestknown flare star is UV Ceti.
Flare star classified as UVCeti type variable starsin variable star catalogues. Flare can happen once every few days much less frequently (in case of Barnardsstar). The nearest star to the solar system is ProximaCentauri which is also aflare star.
Generally red dwarf star are called flare star but little to be possible for browndwarfs.The more massive RSCanumVenaticorum variables are also known to flare but scientist understandthat a companion star disturbs the magneticfield . this companion is amassive planet like the planet Jupiter that orbits the flaring star closely which is observed tothe outburst.5 Figure2: Schematic diagram of a solar flare red and blue lines represent magneticfields carrying solar material of the surface flares occur when these fieldlines meet and reconnect producing hug explosions and heating and accelerationof solar material credit.
: NASA MashallSpace Flight Center.6Afterthe forming offlare mechanism can be explained by an alpha ohm dynamo,a combination of connective motion and differential rotation which power themagnetic field. The magnetic field islinked to the plasma of the star. At these distances the plasma becomes thinand there is evidence that the magnetic field is no longer linked to it. If themagnetic field becomes stronger, the magnetic field lines recombine and reliefenergy a flare occurs.
5 2.2 Spitzersurvey Whenwe present infrared array camera (IRAC, similar to 2deg (2)) and multiband imaging photometer for Spitzer (Mips, similarto 8deg(2)) observation of the Cepheus flare , which is associated with theGould belt at an approximate distance of similar to 300pc.Around 6500 sourcesare detected in all four IRAC bands of which similar to 900 have MIPS 24MU, weidentify 133 young stellar object candidates using color magnitude diagramtechniques and a large number of the YSO candidates are associated with the NGC7023 reflection nebula.
For the nearest neighbor clusteringanalysis identifiedfour small protostellar groups (L1228, L1228N, L1251A and L125B) with 5-15 members each and thelarger NGC 7023 associated with 32 YSO members. The star formation efficiencyfor cores with cluster of proto stars and for those without cluster was foundto be similar to 8% and similar to 1% respectively.7 2.3Dust and GrainIn flare star researchers believethey have identified the main source of cosmicdust gets dumped on earth – meteoroids. Cosmicdust is also known as space dust as well as extraterrestrial dust. A new studyshows that grains of dust left in meteoroid trails are larger than previouslythought.
Some make their way to earth and buzz through the atmosphere, leavingfiery streaks known as shooting stars, along with clouds of dust particles.After the long time these particle were just a few nanometers in size but thesuch particles are actually 10 to 20micrometers in recent by the study of university of Australia.Finally theseparticledrifted down to the troposphere and may have been washed out by rain.
8 2.4AKARISurveyAkariformally known as ASTRO-F, is the second space mission for infrared astronomyfrom the institute of space and Astronautical science (ISAS) of the JapaneseAerospace exploration agency(JAXA). It was ESA participation.9 3. ObjectivesThe objectives of my dissertationwork are as follows· We intend to perform a systematic search on far infrared loopsreported by kiss et al. (2004) and Koenyves et al.(2007) to find an isolatedcavity(flare star cavity) and its possible association using AKARI surveys.
Thecavity which was not studied before will be taken into consideration forfurther study.· The physical properties of this cavitywill be studied and the size, distance, dust color temperature and energyrequired to expel then it will be calculated.· We are interested to find out thepossible sources between the flare star cavity and ISM, as well as thestructure of shaping mechanism will be studied.· The evolution of the flare star cavityand the structure will be discussed using published literatures. The possibleexplanation of the result will be presented.
4. Researchmethodology A explanation of the method and method of analysis is given below Systematic Search (AKARI) Far Infrared Cavity Selection (SIMBAD & ADS) Contour Map Correction(ALADIN) Study of Flux Density Variation (ALADIN) Distance Angle Estimation Dust Color Temperature Calculation Study of possible flare star Study of ShapingMechanism Explanation & Comparison of the result Figure 3:A scheme of methodof study and analysisAt first we examine region ofinterest and then study the physical properties of flare cavity. Here, AKARIrepresent the name of all sky infrared surveys, SIMBAD is the Frenchabbreviation of galactic point sources database provider maintained byStarsburg University, France, ADS is the literature data base providermaintained by Harvard University, USA. The ALADIN is the data reductionsoftware provided by NASA, USA. 4.2 DustColor TemperatureWe worked on selected far infrared cavity at 90 and140 micro meter AKARI maps usingALADIN software to find flux densities as described in Shnee et al. (2005). Thedust color temperature can be obtained by assuming that theinterstellar dust in a single beam is isothermal and that the observed ratio of90 and 140 micro meter emission is due to black body radiation from dust grainsat particular temperature.
The flux density of emission at a wavelength is given by (1)Where is the column density of dust grains, which isa constant, ? is the spectral emissivity index, and is the solid angle subtended at by the detector. Following Dupacet al. (2003), we use the relation (2)To describe the observed inverse relationshipbetween and ?, Here and are free parameters found that the temperaturedependence of the emissivity index fits very well with the hyperbolicapproximating function, with the assumption that the dust emission isopticallythin at 90 µm and 140 µmand that (true for IRAS image), we can write the ratio”R” of the flux densities at 90 µm and 140 µmas, (3)The value of ?depends on dust grain properties as composition,size and compactness. Forreference, ? =0, ? ~1 and ? ~2 for pure black body, the amorphous layer–lattice matter and the metals and crystalline dielectrics respectively.
For asmaller value of 1 can be dropped from both numerator anddenominator of equation and it takes the form R = (4)Taking natural logarithm on bothsides of equation (4) we find the expression for the temperature as, (5) Where,R is given by, R = (6)F(90 µm) and F(140 µm) are the fluxdensities at 90 µm and 140 µm, respectively. In this way we can equation (5)for the determination of the dust grain temperature. 104.3 Preliminaryworks: systematic Search for Flare starForthe efficient analysis iscarried out in the Sky View Virtual Observatory on154far infrared KK-loops accounted by Kiss et al. (2004) and Koenyves et al.
(2007) at 90 and 140 micron AKARI maps. on the source of blind examination andSIMBAD/ADS database, I have preferred region of interest shown below for thefurther learning Figure 4: A 20 x 2oAKARI’Simages at WIDE-S (left) and WIDE-L (right) AKARI maps are shown. All images arecenteredat I(G)=0.5 and I(G)= 69.5 in J2000 coordinate with stern specialcoloring .The darkest color symbolize the region of minimum flux density, andthe brightest the maximum flux density.
When we obtain, FITS(flexible imagetransport system) image of the region of interest will be down loaded andpracticed in the ALADIN9.0 software presented by NASA Extragalactic Databasecentre. The contour maps, In each pixel of values of relative Fluxdensity can be calculated from that software and thensimilar to the next coordinate steps. Finally we will determine the dust colortemperature from previous images ofAKARI.
5. ExpectedOutcomes The anticipatedoutcome will be given as· By the formation of far infrared loopsand flare cavity in thegalaxy will be offered and discussed with the publishedliteratures. The role of far infrared loops is projected to be significant forthe interstellar dust, i.
e. mixture of carbon and silicon compounds.· We imagine to locate the reason of starconstruction in the far infrared sky. 6. WorkPlan Our work plan for 12 month are as given below Work 1-2 month 3-4 months 5-6 Months 7 month 8 Month 9 Month 10 month 11-12 Months Literature Review AKARI Survey Problem Identification Image Reduction Calculation & plotting Modeling & Fitting Multi-wavelength Study Interpretation Thesis Writing 7.
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Torre, Astronomy & Astrophysics,404,L11 (2003) Supervisors ………………………….. Prof. Dr.
BinilAryal HoD, CDP, TU, Kirtipur …………………………………. Mr. A.K. Jha CDP, TU, Kirtipur …………………………………… Prof.R.Weinberger Innsbruck University,Austria