A5052837112- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Astro and Planetary Science
- Astrophysics and Cosmic Phenomena
- Statistical and numerical algorithms
- Advanced Sensor Technologies Research
- Radio Astronomy Observations and Technology
University of Haifa
2023
Ruhr University Bochum
2018-2022
Using the six years of spectroscopic monitoring luminous quasar HE 0435-4312 ($z=1.2231$) with Southern African Large Telescope (SALT), in combination photometric data (CATALINA, OGLE, SALTICAM, and BMT), we determined rest-frame time-delay $296^{+13}_{-14}$ days between MgII broad-line emission ionizing continuum using seven different inference methods. Artefact peaks aliases were mitigated bootstrap method, prior weighting probability function as well by analyzing unevenly sampled mock...
We present the monitoring of AGN continuum and MgII broad line emission for quasar HE 0413-4031 ($z=1.38$) based on six-year by South African Large Telescope (SALT). managed to estimate a time-delay $302.6^{+28.7}_{-33.1}$ days in rest frame source using seven different methods: interpolated cross-correlation function (ICCF), discrete correlation (DCF), $z$-transformed DCF, JAVELIN, two estimators data regularity (Von Neumann, Bartels), $\chi^2$ method. This is below value expected from...
Abstract We present the results of a nearly decade-long photometric reverberation mapping (PRM) survey H α emission line in nearby (0.01 ≲ z 0.05) Seyfert galaxies using small (15–40 cm) telescopes. Broadband filters were used to trace continuum emission, while narrowband tracked -line signal. introduce new PRM formalism determine time delay between and combinations auto- cross-correlation functions. obtain robust delays for 33/80 objects, allowing us estimate broad-line region (BLR) size....
We report 6 yr monitoring of a distant bright quasar CTS C30.10 (z = 0.90052) with the Southern African Large Telescope (SALT). measured rest-frame time-lag $562\pm 2$ days between continuum variations and response Mg II emission line, using Javelin approach. More conservative approach, based on five different methods, imply time delay $564^{+109}_{-71}$ days. This delay, combined other available measurements line mostly for lower redshift sources, shows that reverberation implies...
At the Universitaetssternwarte Bochum near Cerro Armazones we have monitored Seyfert-1 galaxy 3C 120 between September 2014 and March 2015 in BVRI a narrow band filter covering redshifted H alpha line; addition obtained single con-temporary spectrum with FAST at Mt. Hopkins. Compared to earlier epochs is about factor of three brighter, allowing us study shape broad line region (BLR) dust torus high luminosity phase. The analysis light curves yields that echo rather sharp symmetric contrast...
We report the results from a photometric reverberation mapping campaign carried out with C18 telescope at Wise Observatory 2019 to 2020, targeting active galactic nucleus (AGN) MCG 08-11-011. The monitoring was conducted on daily basis specially designed narrow-band filters, spanning optical near-infrared wavelengths ($\sim4000$ $8000${\AA}) and avoiding prominent broad emission lines. aim measure inter-band continuum time lags, determine size-wavelength relation, estimate host-subtracted...
Context. We present the wavelength-resolved reverberation mapping (RM) of combined Mg II and UV Fe broad-line emissions for two intermediate-redshift ( z ∼ 1), luminous quasars, HE 0413-4031 0435-4312, monitored by Southern African Large Telescope (SALT) 1m class telescopes between 2012 2022. Aims. Using a technique, we aim to disentangle emission regions build radius–luminosity (R–L) relation emission, which has so far remained unconstrained. Methods. applied several time-delay...
We report photometry and spectroscopy of the outburst young stellar object ESO-Halpha 99. The was first noticed in Gaia alert Gaia18dvc later by ATLAS. have established light curve with archival ATLAS ``Orange'' filter photometry, data, new V-band J, H, K_s from IRIS UKIRT. brightness has fluctuated several times near maximum. TESS satellite observed 99 high cadence during one these minor minima found fluctuations on timescales days hours. Imaging UKIRT shows outline an outflow cavity, we...
Abstract We present time-series photometry of 21 nearby type II Cepheids in the near-infrared J , H and K s passbands. use this photometry, together with Third Gaia Early Data Release parallaxes, to determine for first time period–luminosity relations (PLRs) from field representatives these old pulsating stars regime. found PLRs be very narrow BL Herculis stars, which makes them candidates precision distance indicators. then archival most accurate obtained eclipsing binaries recalibrate...
We present the results of reverberation monitoring aimed at MgII broad line and FeII pseudocontinuum for luminous quasar CTS C30.10 (z = 0.90052) with Southern African Large Telescope covering years 2012-2021. disentangling UV variability first measurement time delay a distant quasar. used several methods time-delay measurements determined both delays as well performed wavelength-resolved study combination in 2700 - 2900 \AA restframe wavelength range. obtain $275.5^{+12.4}_{-19.5}$ days...
Abstract We monitored the z = 0.158 quasar 3C 273 between 2015 and 2019 in optical ( BVrz ) near-infrared JHK with aim to perform dust reverberation mapping. Accounting for host galaxy accretion disk contributions, we obtained pure light curves . Cross correlations V band yield an average rest-frame delay hot of τ cent ∼ 410 days. This is a factor two shorter than that expected from ring radius R x 900 lt-day reported interferometric studies. The covering (CF) about 8%, much smaller...
EX Lup is the prototype of a class pre-main sequence eruptive stars defined by their repetitive outbursts lasting several months. In 2008 January-September underwent its historically largest outburst, brightening about 4 magnitudes in visual light. previous studies we discovered on-going silicate crystal formation inner disk during but also noticed that measured crystallinity fraction started decreasing after source returned to quiescent phase. Here present new observations 10 $\mu$m...
We present the results of an intensive six-month optical continuum reverberation mapping campaign Seyfert 1 galaxy PG 2130+099 at redshift z=0.063. The ground-based photometric monitoring was conducted on a daily basis with robotic 46cm telescope Wise observatory located in Israel. Specially designed narrowband filters were used to observe central engine active galactic nucleus (AGN), avoiding line contamination from broad-line region (BLR). aim measure inter-band time lags across range and...
We present the results of a nearly decade-long photometric reverberation mapping (PRM) survey H$\alpha$ emission line in nearby ($0.01\lesssim z \lesssim0.05$) Seyfert-Galaxies using small ($15\,\mathrm{cm}-40\,\mathrm{cm}$) telescopes. Broad-band filters were used to trace continuum emission, while narrow-band tracked H$\alpha$-line signal. introduce new PRM formalism determine time delay between and combinations auto- cross-correlation functions. obtain robust delays for 33/80 objects,...
We report the results from a photometric reverberation mapping campaign carried out with C18 telescope at Wise Observatory 2019 to 2020, targeting active galactic nucleus (AGN) MCG 08-11-011. The monitoring was conducted on daily basis specially designed narrow-band filters, spanning optical near-infrared wavelengths ($\sim4000$ $8000$Å) and avoiding prominent broad emission lines. aim measure inter-band continuum time lags, determine size-wavelength relation, estimate host-subtracted AGN...
Optical and near-mid-infrared reverberation mapping data obtained at Universit\"{a}tssternwarte Bochum in Chile with the Spitzer Space Telescope allow us to explore geometry of both H$\alpha$ BLR dust torus for nearby Seyfert-1 galaxy WPVS\,48. On average, variations lag blue AGN continuum by about 18 days, while emission 70 days J+K 90 L+M bands. The IR echoes are sharp, echo is smeared. This together favours a bowl shaped toroidal where sublimation radius defined surface, which virtually...
Optical and near-mid-infrared reverberation mapping data obtained at Universit\"{a}tssternwarte Bochum in Chile with the Spitzer Space Telescope allow us to explore geometry of both H$\alpha$ BLR dust torus for nearby Seyfert 1 galaxy WPVS\,48. On average, variations lag blue AGN continuum by about 18 days, while emission 70 days J+K 90 L+M bands. The IR echoes are sharp, echo is smeared. This together favours a bowl-shaped toroidal where sublimation radius defined bowl surface, which...