Possible evidence of asymmetry in SN 2007rt, a type IIn supernova

An optical photometric and spectroscopic analysis of the slowly-evolving type IIn SN 2007rt is presented, covering a duration of 481 days after discovery. Its earliest spectrum, taken approximately 100 days after the explosion epoch, indicates the presence of a dense circumstellar medium, with which the supernova ejecta is interacting. This is supported by the slowly-evolving light curve. A notable feature in the spectrum of SN 2007rt is the presence of a broad He I 5875 line, not usually detected in type IIn supernovae. This may imply that the progenitor star has a high He/H ratio, having shed a significant portion of its hydrogen shell via mass-loss. An intermediate resolution spectrum reveals a narrow H(alpha) P-Cygni profile, the absorption component of which has a width of 128 km s (1). This slow velocity suggests that the progenitor of SN 2007rt recently underwent mass-loss with wind speeds comparable to the lower limits of those detected in luminous blue variables. Asymmetries in the line profiles of H and He at early phases bears some resemblance to double-peaked features observed in a number of Ib/c spectra. These asymmetries may be indicative of an asymmetric or bipolar outflow or alternatively dust formation in the fast expanding ejecta. In addition, the late time spectrum, at over 240 days post-explosion, shows clear evidence for the presence of newly formed dust.

BONA FIDE, STRONG-VARIABLE GALACTIC LUMINOUS BLUE VARIABLE STARS ARE FAST ROTATORS: DETECTION OF A HIGH ROTATIONAL VELOCITY IN HR CARINAE

We report optical observations of the luminous blue variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si lambda lambda 4088-4116. To match their observed line profiles from 2009 May, a high rotational velocity of nu(rot) similar or equal to 150 +/- 20 km s(-1) is needed (assuming an inclination angle of 30 degrees), implying that HR Car rotates at similar or equal to 0.88 +/- 0.2 of its critical velocity for breakup (nu(crit)). Our results suggest that fast rotation is typical in all strong-variable, bona fide galactic LBVs, which present S-Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the ""LBV minimum instability strip""). We suggest this region corresponds to where nu(crit) is reached. To the left of this strip, a forbidden zone with nu(rot)/nu(crit) > 1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low nu(rot), we propose that LBVs can be separated into two groups: fast-rotating, strong-variable stars showing S-Dor cycles (such as AG Car and HR Car) and slow-rotating stars with much less variability (such as P Cygni and HD 168625). We speculate that supernova (SN) progenitors which had S-Dor cycles before exploding (such as in SN 2001ig, SN 2003bg, and SN 2005gj) could have been fast rotators. We suggest that the potential difficulty of fast-rotating Galactic LBVs to lose angular momentum is additional evidence that such stars could explode during the LBV phase.

Near-infraread observation of supernovae with the Nordic Optical Telescope (NOT)

Supernova (SN) is an explosion of a star at the end of its lifetime. SNe are classified to two types, namely type I and II through the optical spectra. They have been categorised based on their explosion mechanism, to core collapse supernovae (CCSNe) and thermonuclear supernovae. The CCSNe group which includes types IIP, IIn, IIL, IIb, Ib, and Ic are produced when a massive star with initial mass more than 8 M⊙ explodes due to a collapse of its iron core. On the other hand, thermonuclear SNe originate from white dwarfs (WDs) made of carbon and oxygen, in a binary system. Infrared astronomy covers observations of astronomical objects in infrared radiation. The infrared sky is not completely dark and it is variable. Observations of SNe in the infrared give different information than optical observations. Data reduction is required to correct raw data from for example unusable pixels and sky background. In this project, the NOTCam package in the IRAF was used for the data reduction. For measuring magnitudes of SNe, the aperture photometry method with the Gaia program was used. In this Master’s thesis, near-infrared (NIR) observations of three supernovae of type IIn (namely LSQ13zm, SN 2009ip and SN2011jb), one type IIb (SN2012ey), in addition to one type Ic (SN2012ej) and type IIP (SN 2013gd) are studied with emphasis on luminosity and colour evolution. All observations were done with the Nordic Optical Telescope (NOT). Here, we used the classification by Mattila & Meikle (2001) [76], where the SNe are differentiated by the infrared light curves into two groups, namely ’ordinary’ and ’slowly declining’. The light curves and colour evolution of these supernovae were obtained in J, H and Ks bands. In this study, our data, combined with other observations, provide evidence to categorize LSQ13zm, SN 2012ej and SN 2012ey as being part of the ordinary type. We found interesting NIR behaviour of SN 2011jb, which lead it to be classified as a slowly declining type.

TESTING THE DISTANCE-DUALITY RELATION WITH GALAXY CLUSTERS AND TYPE Ia SUPERNOVAE

In this Letter, we propose a new and model-independent cosmological test for the distance-duality (DD) relation, eta = D(L)(z)(1 + z)(-2)/D(A)(z) = 1, where D(L) and D(A) are, respectively, the luminosity and angular diameter distances. For D(L) we consider two sub-samples of Type Ia supernovae (SNe Ia) taken from Constitution data whereas D(A) distances are provided by two samples of galaxy clusters compiled by De Filippis et al. and Bonamente et al. by combining Sunyaev-Zeldovich effect and X-ray surface brightness. The SNe Ia redshifts of each sub-sample were carefully chosen to coincide with the ones of the associated galaxy cluster sample (Delta z < 0.005), thereby allowing a direct test of the DD relation. Since for very low redshifts, D(A)(z) approximate to D(L)(z), we have tested the DD relation by assuming that. is a function of the redshift parameterized by two different expressions: eta(z) = 1 + eta(0)z and eta(z) = 1 +eta(0)z/(1 + z), where eta(0) is a constant parameter quantifying a possible departure from the strict validity of the reciprocity relation (eta(0) = 0). In the best scenario (linear parameterization), we obtain eta(0) = -0.28(-0.44)(+0.44) (2 sigma, statistical + systematic errors) for the De Filippis et al. sample (elliptical geometry), a result only marginally compatible with the DD relation. However, for the Bonamente et al. sample (spherical geometry) the constraint is eta(0) = -0.42(-0.34)(+0.34) (3 sigma, statistical + systematic errors), which is clearly incompatible with the duality-distance relation.

Kinematic constraints to the transition redshift from supernovae type Ia union data

The kinematic approach to cosmological tests provides direct evidence to the present accelerating stage of the Universe that does not depend on the validity of general relativity, as well as on the matter-energy content of the Universe. In this context, we consider here a linear two-parameter expansion for the decelerating parameter, q(z)=q(0)+q(1)z, where q(0) and q(1) are arbitrary constants to be constrained by the union supernovae data. By assuming a flat Universe we find that the best fit to the pair of free parameters is (q(0),q(1))=(-0.73,1.5) whereas the transition redshift is z(t)=0.49(-0.07)(+0.14)(1 sigma) +0.54-0.12(2 sigma). This kinematic result is in agreement with some independent analyses and more easily accommodates many dynamical flat models (like Lambda CDM).

Venäjän suhde ETYJ:iin

Tässä diplomityössä tarkastellaan Venäjän suhdetta ETYJ:iin. Tarkoituksena on tarkastella sitä, miten Venäjä rakentaa ja muotoilee oman näkemyksensä ETYJ:in toimintaan ja esittää näkemyksensä muille. Venäjä rakentaa todellisuutta ja valtasuhdetta omilla intressialueillaan käyttämällä viestintää välineenä. Venäjän ja länsimaiden ETYJ:in puitteissa käyttämien puheenvuorojen voidaan ajatella olevan diskurssikamppailua siitä, miten arvoyhteisön normeja voidaan soveltaa ja mikä on hyväksyttävää toimintaa. Tutkimuksen tavoitteena on pyrkiä selvittämään Venäjän suhdetta ETYJ:iin tutkimalla Venäjän ulkopoliittista diskurssia ETYJ:in toiminnasta Itä-Euroopassa ja Georgian tilanteeseen liittyen, sekä presidentti Medvedevin aloitteessa uudesta eurooppalaisesta turvallisuusjärjestelystä. Yleisenä teoreettisena lähtökohtana suhteiden tarkasteluun käytetään konstruktivismia. Metodina on käytetty kriittistä diskurssianalyysia. Pääasiallisena lähteenä on käytetty Venäjän lausuntoja ETYJ:issä vuosilta 2006–2010. Venäjän näkökulmasta kiistanalaisten asioiden luonne liit-tyy suoraan tai läheisesti materiaalisiin tai muuten konkreettisesti ilmeneviin intresseihin. Venäläisen lähestymistavan mukaan asioista neuvotellaan niin, että vastakkainasettelun omaisesta lähtökohdasta tingitään ja tehdään kompromisseja, sekä sitoudutaan vastavuoroisesti. Länsimaisesta näkökulmasta kiistanalaisuus liittyy arvoihin tai normeihin, joiden kautta pyritään löytämään vuorovaikutteisesti muuntumiseen pohjautuvia ratkaisuja. Venäjän kielenkäytöstä ei ole löydettävissä suoranaista piilotettua agendaa, mutta vivahde piilovaikuttamisesta tulee vastaan Itä-Euroopan maita koskevissa lausunnoissa. Vaikutelma on sellainen, että vaikuttamisen kohde on venäläinen yleisö. Teemana on silloin kansallisen identiteetin ja maailmanpolitiikan vaikuttajan roolin rakentaminen. Venäjän suhde ETYJ:iin tulee varmasti pysymään kompleksisena, mutta sen pyrkimys läsnäoloon päätöksenteossa pakottanee sen jatkossakin tekemään kompromisseja omien intressiensä suhteen.

Yleispiirteinen kartta Iin pitäjästä

Kartan esitystekniikka: maastokartta.

Nijden terwellisten sanain muoto, 2 Tim. 1:13. Sijnä järjestyxesä kuin d. Lutheruxen Catechismus sen päkappaleisa sisällänspitä, nijden enimmäin catechismuxen selittäitten johdatuxen jälkeen, edeswetänyt ja kokoonpannut yxinkertaisisa kysymyxisä ja wastauxisa. Wuonna 1782. Eric Frosterus v. past. ja cappalainen Haukiputan kappelilla, Iin pitäjäsä

Arkit: A-M8 N6

Nijden terwellisten sanain muoto, 2 Tim. 1:13. Sijnä järjestyxesä kuin d. Lutheruxen Catechismus sen päkappaleisa sisällänspitä, nijden enimmäin catechismuxen selittäitten johdatuxen jälkeen, edeswetänyt ja kokoonpannut yxinkertaisisa kysymyxisä ja wastauxisa. Wuonna 1782. Eric Frosterus v. past. ja cappalainen Haukiputan kappelilla, Iin pitäjäsä

Arkit: A-M8 N6