A5101871618- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Astronomy and Astrophysical Research
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Laser Applications
National Radio Astronomy Observatory
2023
Leibniz Institute for Astrophysics Potsdam
2008-2013
Mount Stromlo Observatory
2007-2008
Australian National University
2007
We report new constraints on the local escape speed of our Galaxy. Our analysis is based a sample high velocity stars from RAVE survey and two previously published datasets. use cosmological simulations disk galaxy formation to motivate assumptions shape distribution, allowing for significantly more precise measurement compared previous studies. find that lies within range $498\kms < \ve 608 \kms$ (90 per cent confidence), with median likelihood $544\kms$. The fact $\ve^2$ greater than...
We have used spectra of hot stars from the RAVE Survey in order to investigate visibility and properties five diffuse interstellar bands previously reported literature. The spectroscopic survey for Galactic structure kinematics records CCD covering 8400–8800 Å wavelength region at 7500 resolving power. are obtained with UK Schmidt AAO, equipped 6dF multi-fiber positioner. DIB 8620.4 is by far strongest cleanest all DIBs occurring within range, no interference underlying absorption stellar...
We analyze the distribution of G and K type stars towards Galactic poles using RAVE ELODIE radial velocities, 2MASS photometric star counts, UCAC2 proper motions. The combination 3D kinematic data allows us to disentangle describe vertical dwarfs, sub-giants giants their kinematics. identify discontinuities within kinematics magnitude counts that separate thin disk, thick disk a hotter component. respective scale heights are 225 ± 10 pc 1048 36 pc. also constrain luminosity function...
ABSTRACT Classical novae are shock-powered multiwavelength transients triggered by a thermonuclear runaway on an accreting white dwarf. V1674 Her is the fastest nova ever recorded (time to declined two magnitudes t2 = 1.1 d) that challenges our understanding of shock formation in novae. We investigate physical mechanisms behind emission from GeV γ-rays cm-band radio using coordinated Fermi-LAT, NuSTAR, Swift, and VLA observations supported optical photometry. Fermi-LAT detected short-lived...
Context. Galactic open clusters (OCs) mainly belong to the young stellar population in Milky Way disk, but are there groups and complexes of OCs that possibly define an additional level hierarchical star formation? Current compilations too incomplete address this question, especially regarding radial velocities (RVs) metallicities ([M/H]).
We have analyzed the phase space distribution of a sample about 900 non-kinematically selected low metallicity stars in solar vicinity. The primarily represent thick disk and halo populations Milky Way. aim to identify overdensely populated regions space, which we interpret as signatures star streams passing close Sun. search was conducted constructed from angular momenta eccentricities stellar orbits. Besides recovering all well known disk, isolated four statistically significant...
V745 Sco is a Galactic symbiotic recurrent nova with eruptions in 1937, 1989 and 2014. We study the behavior of at radio wavelengths (0.6-37,GHz), covering both its 2014 informed by optical, X-ray, $\gamma$-ray data. The light curves are synchrotron-dominated. Surprisingly, compared to expectations for synchrotron emission from explosive transients such as supernovae, spanning 0.6-37 GHz all peak around same time ($\sim$18-26 days after eruption) similar flux densities (5-9 mJy).We model...
Lightcurves of many classical novae deviate from the canonical "fast rise - smooth decline" pattern and display complex variability behavior. We present first TESS-space-photometry-based investigation this phenomenon. use TESS Sector 41 full-frame images to extract a lightcurve slow Galactic nova V606 Vul that erupted nine days prior start observations. The covers two major peaks was reached 19 after eruption. its brightest visual magnitude V=9.9 in second peak 64 eruption onset, following...