Search Publications
Probing the Variation of Reverberation Lags along with X-Ray Flux in the AGN Mrk 704
Sriram, K.; Choi, C. S.; Agrawal, Vivek K. +2 more
Understanding the variation of lags with respect to the X-ray flux is important to explore the geometry of the inner region of the accretion disk in AGNs. We performed frequency-lag, energy-lag and spectral studies for two sets of observations, in order to investigate the variations in lags with respect to X-ray flux in the AGN source Mrk 704 usin…
Soft excess in AGN with relativistic X‑ray reflection
Mathew, Blesson; Dewangan, Gulab C.; Ezhikode, Savithri H. +1 more
The soft X‑ray excess, emission below 2 keV over the X‑ray power‑law, is a marked spectral component in the X‑ray spectra of many Seyfert 1 galaxies. We investigate if the observed soft X‑ray excess in a sample of Seyfert 1s is in accordance with the prediction of the relativistic reflection model by analyzing the XMM‑Newton and NuSTAR spectra. Th…
XGAPS: a sub-arcsec cross-match of galactic plane surveys
Knigge, C.; Groot, P. J.; Monguió, M. +5 more
We present a sub-arcsec cross-match of Gaia Data Release 3 (DR3) against the INT Galactic Plane Surveys (IGAPS) and the United Kingdom Infrared Deep Sky Survey (UKIDSS). The resulting cross-match of Galactic Plane Surveys (XGAPS) provides additional precise photometry (URGO, g, r, i, Hα, J, H, and K) to the Gaia photometry. In building …
Turbulent dipolarization regions in the Earth's magnetotail: ion fluxes and magnetic field changes
Kronberg, Elena A.; Blöcker, Aljona; Fedun, Viktor +4 more
In this work, we consider the dynamics of ion fluxes and magnetic field changes in turbulent regions of magnetotail dipolarizations. The data from the Cluster-II mission (magnetic field measurements from fluxgate magnetometers and energetic charged particle observations from RAPID spectrometers) were used for the analysis. We study individual even…
VLBI astrometry on the white dwarf pulsar AR Scorpii
Zhang, Bo; Yang, Jun; An, Tao +12 more
AR Scorpii (AR Sco), the only-known radio-pulsing white dwarf binary, shows unusual pulsating emission at the radio, infrared, optical, and ultraviolet bands. To determine its astrometric parameters at the radio band independently, we conducted multi-epoch Very Long Baseline Interferometry (VLBI) phase-referencing observations with the European VL…
A Survey for C II Emission-line Stars in the Large Magellanic Cloud. II. Final Results and the Origin of C II Emission in [WC] Spectra
Massey, Philip; Morrell, Nidia; Neugent, Kathryn F. +2 more
We present the final results of an imaging and spectroscopic search for stars in the Large Magellanic Cloud (LMC) with C II λλ7231, 7236 emission lines. The goal is to identify and study [WC11] stars, the coolest of the low-mass Wolf-Rayet sequence, and a subset of central stars of planetary nebulae where the C II lines are known to be especially …
V1507 CYGNI (HD187399): A Highly Evolved, Enigmatic Interacting Binary System with an Eccentric Orbit
Davidge, T. J.
The properties of the interacting, eccentric orbit binary V1507 Cyg (HD187399) are examined with spectra that cover wavelengths from 0.63-0.68 µm. The spectrum of the brightest star is similar to that of the B8 I star β Ori, although with absorption lines that show substructure possibly related to a varying tidal field. The bulk of the Hα em…
GBB-Nadir and KLIMA: Two Full Physics Codes for the Computation of the Infrared Spectrum of the Planetary Radiation Escaping to Space
Dinelli, Bianca Maria; Del Bianco, Samuele; Castelli, Elisa +7 more
In 2019 the Far-Infrared Outgoing Radiation Understanding and Monitoring (FORUM) mission was selected to be the 9th Earth Explorer mission of the European Space Agency (ESA). In the preparatory phase of the mission there was the need for accurate and versatile codes to compute the spectrally resolved Earth radiation escaping to space ( outgoing lo…
Reconstructing the Volume Density Profile of Prestellar Cores with the Anisotropic Inverse Abel Transform Method
Zhang, Yapeng; Liu, Zhengdong; An, Weiming +2 more
Most studies of the 3D density structure of prestellar cores have used isotropic evolution models, which are projected into 2D for direct comparison with observation data. In this study, we introduced the anisotropic inverse Abel transform method for reconstructing the 3D volume density profile of prestellar cores. We demonstrated that this approa…
NGC 1193 ve NGC 1798 Açık Kümelerinin CCD UBV ve Gaia Analizleri
Bilir, Selçuk; Yontan, Talar; Taşdemir, Seval
Bu çalışmada, NGC 1193 ve NGC 1798 yaşlı açık kümelerinin fotometrik, astrometrik ve kinematik analizleri gerçekleştirilmiştir. Analizlerde Gaia uydusunun 3. erken veri sürümüyle Gaia EDR3 CCD UBV gözlemsel verileri birlikte kullanılmıştır. Kümeye üye yıldızların belirlenmesinde, yıldızların astrometrik verilerinden faydalanılmıştır. Üyelik olasıl…