A connection between γ\gamma-ray and parsec-scale radio flares in the blazar 3C 273

We present a comprehensive 5-43 GHz VLBA study of the blazar 3C 273 initiated after an onset of a strong $\gamma$-ray flare in this source. We have analyzed the kinematics of new-born components, light curves, and position of the apparent core to pinpoint the location of the $\gamma$-ray emission. Estimated location of the $\gamma$-ray emission zone is close to the jet apex, 2 pc to 7 pc upstream from the observed 7 mm core. This is supported by ejection of a new component. The apparent core position was found to be inversely proportional to frequency. The brightness temperature in the 7 mm core reached values up to at least $10^{13}$ K during the flare. This supports the dominance of particle energy density over that of magnetic field in the 7 mm core. Particle density increased during the radio flare at the apparent jet base, affecting synchrotron opacity. This manifested itself as an apparent core shuttle along the jet during the 7 mm flare. It is also shown that a region where optical depth decreases from $\tau\sim1$ to $\tau<<1$ spans over several parsecs along the jet. The jet bulk flow speed estimated at the level of 12c on the basis of time lags between 7 mm light curves of stationary jet features is 1.5 times higher than that derived from VLBI apparent kinematics analysis.Comment: Accepted for publication in MNRAS. 17 pages, 15 figures, 10 tables, with supplementary materials attache

The Relation between Radio Polarization and Gamma-ray Emission in AGN Jets

We have compared the parsec-scale jet linear polarization properties of the Fermi LAT-detected and non-detected sources in the complete flux-density-limited (MOJAVE-1) sample of highly beamed AGN. Of the 123 MOJAVE sources, 30 were detected by the LAT during its first three months of operation. We find that during the era since the launch of Fermi, the unresolved core components of the LAT-detected jets have significantly higher median fractional polarization at 15 GHz. This complements our previous findings that these LAT sources have higher apparent jet speeds, brightness temperatures and Doppler factors, and are preferentially found in higher activity states.Comment: 6 pages, 3 figures, to appear in the proceedings of "High Energy Phenomena In Relativistic Outflows II" (Buenos Aires, Argentina, October 26-30, 2009) International Journal of Modern Physics

Nopea mittakaava- ja valaistusinvariantti metodi alueiden luokitteluun

This work describes how to find 3D objects in 2D images. The images may contain various illumination conditions and backgrounds. Furthermore the distance and the rotation of the camera with respect to the object can be arbitrary. The method described in this work provides a way to reduce computation time of the 3D object localization problem by searching only from the regions of the image that include a combination of the most common colors of the object. The accuracy and speed of the implementation is tested on images taken under various illuminations and backgrounds.Tämä työ kuvailee miten kolmiulotteisia esineitä voi löytää kaksiulotteisista kuvista. Kuvat voivat sisältää vaihtelevia valaistusolosuhteita ja taustoja. Lisäksi kameran etäisyys ja avaruuskulma suhteessa esineeseen on mielivaltainen. Tässä työssä esitetty menetelmä antaa tavan vähentää kolmiulotteisen esineen löytämisen laskenta-aikaa etsimällä ainoastaan niistä kohdista, joissa on yhdistelmä esineen yleisimpiä värejä. Menetelmän tarkkuus ja nopeus on testattu kuvilla, jotka on otettu erilaisilla valaistuksilla ja taustoilla

An Exceptional Radio Flare in Markarian 421

In September 2012, the high-synchrotron-peaked (HSP) blazar Markarian 421 underwent a rapid wideband radio flare, reaching nearly twice the brightest level observed in the centimeter band in over three decades of monitoring. In response to this event we carried out a five epoch centimeter- to millimeter-band multifrequency Very Long Baseline Array (VLBA) campaign to investigate the aftermath of this emission event. Rapid radio variations are unprecedented in this object and are surprising in an HSP BL Lac object. In this flare, the 15 GHz flux density increased with an exponential doubling time of about 9 days, then faded to its prior level at a similar rate. This is comparable with the fastest large-amplitude centimeter-band radio variability observed in any blazar. Similar flux density increases were detected up to millimeter bands. This radio flare followed about two months after a similarly unprecedented GeV gamma-ray flare (reaching a daily E>100 MeV flux of (1.2 +/- 0.7)x10^(-6) ph cm^(-2) s^(-1)) reported by the Fermi Large Area Telescope (LAT) collaboration, with a simultaneous tentative TeV detection by ARGO-YBJ. A cross-correlation analysis of long-term 15 GHz and LAT gamma-ray light curves finds a statistically significant correlation with the radio lagging ~40 days behind, suggesting that the gamma-ray emission originates upstream of the radio emission. Preliminary results from our VLBA observations show brightening in the unresolved core region and no evidence for apparent superluminal motions or substantial flux variations downstream.Comment: 5 pages, 8 figures. Contributed talk at the meeting "The Innermost Regions of Relativistic Jets and Their Magnetic Fields", Granada, Spain. Updated to correct author list and reference

The climate change movement and political parties: Mechanisms of social media and interaction during the 2019 electoral period in Finland

Peer reviewe

CRM systems value for a company

Tämän kandidaatintutkielman tavoitteena on tutkia CRM-järjestelmän hyötyjä yrityksille. CRM-järjestelmiä käytetään yleisesti hyödyksi asiakastiedon hallinnassa. Tänä päivänä yrityksillä on mahdollisuus päästä käsiksi valtavaan määrään asiakastietoa. CRM-järjestelmä on yrityksen kokonaisvaltainen työkalu tämän tiedon analysointiin, levittämiseen ja prosessointiin. Sen tarkoituksena on tuottaa asiakastietomassasta oleellista tietoa ja helpottaa tämän tiedon jakamista sinne, missä tietoa kulloinkin tarvitaan. Hyvin toimiva järjestelmä voi tuottaa lisäarvoa yritykselle toimintojen tehostuneisuuden kautta, sekä parantamalla esimerkiksi myynnin tuloksia. Konseptin monimutkaisuuden takia todellisuus eroaa tästä kuvauksesta. Tutkimuksen case-yrityksillä CRM-järjestelmät toimivat vahvasti myyntiorganisaatioiden työkaluina, missä järjestelmän suurimmat hyödyt esiintyvät. Järjestelmän avulla kohdistettu myynti ja markkinointi tuottavat parempia tuloksia. Järjestelmä on myös mahdollistanut asiakaspalveluprosessiin tehokkuutta, mikä näkyy kustannusten alentumisena. Yrityksissä CRM-järjestelmän hyödyntäminen on hyvin erilaista ja täyden potentiaalin saavuttaminen on haastavaa. CRM-järjestelmistä voi olla tutkimukseni mukaan lisäarvoa yritykselle, mutta se vaatii järjestelmän kokonaisvaltaista omaksumista organisaatiossa. Toimiva kokonaisvaltainen järjestelmä vaatii yritykseltä merkittäviä toimia niin johdolta kuin työntekijöiltä. Toisaalta järjestelmästä näyttää olevan hyötyä myös pienemmässä mittakaavassa.Purpose of this bachelor’s degree is to study CRM systems value for a company. CRM systems are in wide use in customer knowledge management. Nowadays companies have huge amounts of data in their possession. CRM system is a holistic tool for analysing, distribution and processing this information. Its function is to generate useful information from excess amount of customer data. Successfully working CRM system can produce added value for the company. For example, by benefits coming from optimizing costs or by helping sales team close more deals. CRM has its possibilities, but its complexity often leads to questionable results in practice. Studied case companies show that CRM system is strongly related to sales which lead to systems biggest benefits. System allows company to focus their marketing and sales to more potential segments and customers. Holistic CRM system creates efficiency to customer service, further decreasing costs. Companies CRM policy seems to alternate considerably, and full potential is often not achieved. This study shows that CRM system can create added value for a company, but it requires complete holistic integration to organization. Management and employs both need to engage fully to achieve value from the CRM system. On the other hand, CRM systems can be beneficial in lower scale

The off-axis jet structure in Mrk 501 at mm-wavelengths

We present results from 43 GHz (VLBA, six epochs from 2012.2 to 2013.2) and 86 GHz (GMVA, one epoch in 2012.4) observations toward the basis of the jet in the TeV Blazar Mrk 501. The 43-GHz data analysis reveals a new feature located northeast of the radio core, with a flux density of several tens of mJy, perpendicularly to the jet axis. The 86-GHz image shows the jet feature located 0.75 mas southeast of the radio core, which is consistent with the previous result. The location of Gaussian model for 0.75 mas feature does not coincide with those for the jets in the 43-GHz image, however, a distribution of emission is found. We also discuss the spectral indices of the core, the northeast feature, and the jet feature between 43 GHz and 86 GHz, which show flat-to-steep, steep, and flat-to-invert, respectively.Comment: 4 pages, 2 figures; proceedings of the 12th European VLBI Network Symposium and Users Meeting, 7-10 October 2014, Cagliari, Ital