Call for applications to doctoral programs 2024A in UST KASI School

Korea Astronomy and Space Science Institute (KASI) School via the University of Science and Technology (UST) is offering doctoral (direct and integrated) scholarships starting from March 2024. PhD scholarships are provided with a competitive salary of about $1600 per month for the doctoral program. KASI is located in Daejeon, a high tech, educational and research oriented city. Convenient accommodation would be provided to students for the first 3 years in the campus.

KASI is actively involved in various fields of astronomy and astrophysics, from astronomical instrumentation to observation and theory, and participates in international collaborative and stand-alone projects including GMT, ALMA, SDSS4, DESI, LSST, KMTNet, and KVN. This semester KASI is accepting applications for the following research area:

• Radio Astronomy (supervisor: Prof. Sang-Sung Lee (sslee@kasi.re.kr)

• Cosmology (supervisor: Prof. Arman Shafieloo (shafieloo@kasi.re.kr)

and for the detailed description of the specific research topics, see the list attached or in our major homepage (https://www.kasi.re.kr/eng/pageView/140)

We encourage qualified international students to apply. Competent students with BSc degrees can apply for an integrated PhD program. Students with MSc degrees may apply directly to the PhD program.

Questions on each research area should be sent to each assigned professor, while other questions are sent to the Chief Major Professor (Sang-Sung Lee, sslee@kasi.re.kr). For more information of application, please see the UST web page (https://ust.ac.kr/admission_eng.do). Applications are considered only if they are submitted during October 12 to November 1 (17:00 KST).

Best regards,

Sang-Sung Lee

Chief Major Professor

1. Prof. Sang-Sung Lee (sslee@kasi.re.kr)

Origins of Gamma-ray Flares in Active Galactic Nuclei: 

Gamma-ray flares of Active Galactic Nuclei (AGN) are known to generate in innermost regions of relativistic jets which radiate in whole ranges of electromagnetic spectra due to synchrotron radiation, synchrotron self absorption, inverse-Compton scattering, Doppler boosting etc. Here we may raise two questions on the natures of the gamma-ray flares of AGN such as: a) What is the basic cause of the gamma-ray flares from AGNs? b) What is the physical process of the causes? For the first question, there are several suggestions like 1) a relativistic jet of high energy plasma (Marscher et al. 2008), 2) Doppler boosting of synchrotron radiation of the jet (Dermer 1995), 3) inverse Compton scattering by relativistic electrons, etc. For the second question, we may find some candidates and detail mechanism for the gamma-ray flares such as 1) compression and heating of the plasma in the relativistic jets, 2) generation of the relativistic particles, 3) rapid variability in flux and magnetic field. In order to answer to the questions, we may conduct either 1) studies of large samples of flaring AGNs for investigating statistics and correlation of observed properties (Lister et al. 2011), 2) multi-wavelength observations of individual objects for testing time profiles of flares (Jorstad et al. 2010), for studying physical properties of emission features (jet knots) (Agudo et al. 2011), and studying evolution of SEDs (Wehrle et al. 2013), or 3) polarization observations for looking at magnetic field environments (Jorstad et al. 2013). Possible explanations of the gamma-ray flares in AGNs are a) shocks-in-jets propagating within jet flow and b) bending of the whole jets. For both cases, we should expect changes in polarization, luminosity, particle distribution, and structures of jets at mas-scale. The multifrequency simultaneous VLBI/SD observations with KVN are the best tool for detecting such changes correlated with gamma-ray flares. The Interferometric Monitoring of Gamma-ray Bright AGNs (iMOGABA) project (Lee et al. 2016) has been launched in 2015 as a key science program of Korean VLBI Network (KVN). This project uses KVN for monthly interferometric monitoring of morethan 30 gamma-ray bright AGN at 22, 43, 86, and 129 GHz simultaneously (Lee et al. 2016). The iMOGABA aims especially at the potential connection between gamma-ray outbursts and the formation of new jet components, by investigating the potential correlation of the gamma-ray light curves with the brightness and mas-scale structures of the inner jets. The monitoring cadence of a month and the observing frequencies of 22-129GHz make this project unique in studying the gamma-ray flaring AGN.

2. Prof. Arman Shafieloo (shafieloo@kasi.re.kr)

This project is for a PhD or integrated PhD student.

We are looking for competent and enthusiastic PhD candidates to work on physical cosmology. A successful candidate will become officially involved with DESI (Dark Energy Spectroscopic Instrument) and Rubin (former Large Synoptic Survey Telescope) surveys and the project will include studying and performing research on different aspects of physical cosmology such as testing early universe scenarios and studying dark energy using large scale structure and other cosmological data. Developing advanced statistical methods of data analysis (data mining, machine learning, regression approaches) will be a major part of the research during the PhD project or integrated-PhD.