Search Publications
Star formation in the high-extinction Planck cold clump PGCC G120.69+2.66
Djupvik, Anlaug A.; Comerón, Fernando; Yun, João L.
We investigate the star formation occurring in the Planck Galactic cold clump PGCC 120.69+2.66. Near-infrared JHKs images and K-band spectroscopy obtained with NOTCam at the Nordic Optical Telescope complemented with archive data are used to study the stellar content. In addition, millimetre line CO and CS spectra were obtained with the Onsala 20 …
Validation of the RR Lyrae period determination in the Pan-STARRS PS1 3π survey with K2
Szabó, Róbert; Molnár, László; Forró, Adrienn +2 more
Context. The Pan-STARRS 3π survey has detected hundreds of thousands of variable stars thanks to its coverage and 4-year time span, even though the sampling of the light curves is relatively sparse. These light curves contain only 10–15 detections in each of the five filters (g, r, i, z, y). During the K2 mission, the Kepler space telescope observ…
Radial Distribution of Electron Quasi-thermal Noise in the Inner Heliosphere
Chen, Ling; Li, Yi-Lun; Wu, De-Jin
The electron population in the solar wind plasma can be described with three different components: a core, a halo, and a magnetic field aligned strahl. The electron quasi-thermal noise (QTN) is investigated by using an electron population model consisting of a core with a Maxwellian distribution and a halo with a kappa distribution, based on the e…
Soft X-Ray Energy Spectra in the Wide-field Galactic Disk Area Revealed with HaloSat
Kaaret, Philip; Angelini, Lorella; Mitsuishi, Ikuyuki +3 more
We analyzed data from HaloSat observations for five fields in the Galactic disk located far away from the Galactic center (135° < l < 254°) to understand the nature of soft X-ray energy emission in the Galactic disk. The fields have 14° diameter and were selected to contain no significant high-flux X-ray sources. All five HaloSat soft X-ray …
A Radio-loud Semiregular Variable
Luque-Escamilla, Pedro L.; Martí, Josep
As a byproduct of our search for Galactic stellar systems with gamma-ray emission, we have identified an unrelated cool and evolved star (IRC-10412) that attracted our attention due to its strong radio emission level with a spectral index matching, almost perfectly, the canonical +0.6 value expected from an ionized stellar wind. A follow-up observ…
Suprathermal Outflowing H+ Ions in the Lobe Driven by an Interplanetary Shock: 2. A 3D Global Hybrid Simulation
Mouikis, C. G.; Wang, Chih-Ping; Wang, Xueyi +2 more
We conduct a global hybrid simulation of an observation event to affirm that an interplanetary (IP) shock can drive significant suprathermal (tens to hundreds of eV) H+ outflows from the polar cap. The event showed that a spacecraft in the lobe at ∼6.5 RE altitude above the polar cap observed the appearance of suprathermal ou…
Study of hydrated asteroids via their polarimetric properties at low phase angles
Hasegawa, Sunao; Watanabe, Makoto; Ishiguro, Masateru +11 more
Context. Ch-type asteroids are distinctive among other dark asteroids in that they exhibit deep negative polarization branches (NPBs). Nevertheless, the physical and compositional properties that cause their polarimetric distinctiveness are less investigated. Aims. We aim to investigate the polarimetric uniqueness of Ch-type asteroids by making da…
Spectroflat: A generic spectrum and flat-field calibration library for spectro-polarimetric data
Feller, A.; Iglesias, F. A.; Doerr, H. -P. +1 more
Context. Flat-fielding spectro-polarimetric data with one spatial and one spectral dimension is inherently difficult as the imprint of the spectral lines needs to be separated from other wavelength-dependent instrumental effect (e.g., fringes or prefilter profiles) and wavelength-independent effects (e.g., dust and sensor response). Current approa…
Analysis of Overtones in Transverse Oscillations of Coronal Loops of an Active Region
K., Safna Banu; Maurya, Ram Ajor
We investigate the fundamental mode and overtones in the transverse oscillations of coronal loops associated with an active region using intensity observations taken by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). The fundamental periods of the two selected coronal loops are found to be 17.0 minutes and 15.2…
Role of nonlinear structures and associated turbulence generation dayside magnetosphere reconnection sites
Sharma, R. P.; Pathak, Neha; Sharma, Suresh C. +1 more
A numerical simulation is implemented to investigate the role of whistler wave in the presence of the ponderomotive force-driven density modification and the magnetic field perturbation due to preexisting magnetic islands. The dynamical equation governing the whistler waves is derived and solved using numerical methods to assess their role. The si…