English
Related papers

Related papers: Intra-Day Variability and the Interstellar Medium …

200 papers

We study the relationship between the mid-infrared and sub-mm variability of deeply embedded protostars using the multi-epoch data from the Wide Infrared Survey Explorer ($WISE$/NEOWISE) and the ongoing James Clerk Maxwell Telescope (JCMT)…

Temporal offsets between the time series of solar activity indicators provide important clues regarding the physical processes responsible for the cyclic variability in the solar atmosphere. Hysteresis patterns generated between any two…

Solar and Stellar Astrophysics · Physics 2015-06-18 K. B. Ramesh , N Vasantharaju

We present observations of the 22 GHz water vapor megamasers in the Circinus galaxy made with the Tidbinbilla 70m telescope. These observations confirm the rapid variability seen earlier by Greenhill et al (1997). We show that this rapid…

Astrophysics · Physics 2009-11-10 J. N. McCallum , S. P. Ellingsen , D. L. Jauncey , J. E. J. Lovell , L. J. Greenhill , .

While the data analysis of $\gamma$-ray telescopes has now become more robust, some signals may be misinterpretations of a time-variable foreground emission from the Solar System, induced by low-energy cosmic-ray interactions with…

High Energy Astrophysical Phenomena · Physics 2023-10-13 Thomas Siegert

We present results of the analysis of interstellar scintillation in PSR B0823+26. Observations were conducted at a frequency of 1.7 GHz using the 32-m Torun Centre for Astronomy radio telescope. More than 50 observing sessions, lasting on…

High Energy Astrophysical Phenomena · Physics 2013-10-31 M. Daszuta , W. Lewandowski , J. Kijak

To understand the correlation and the radiation mechanism of flare emission in different wavelength bands, we have coordinated a number of telescopes to observe SgrA* simultaneously. We focus only on one aspect of the preliminary results of…

Astrophysics of Galaxies · Physics 2010-04-05 F. Yusef-Zadeh , J. Miller-Jones , D. Roberts , M. Wardle , M. Reid , K. Dodds-Eden , D. Porquet , N. Grosso

Solar activity has a cyclic nature with the ~11-year Schwabe cycle dominating its variability on the interannual timescale. However, solar cycles are significantly modulated in length, shape and magnitude, from near-spotless grand minima to…

Solar and Stellar Astrophysics · Physics 2023-03-29 Akash Biswas , Bidya Karak , Ilya Usoskin , Eckhard Weisshaar

We argue that earth's short-term temperature anomalies and the solar flare intermittency are linked. The analysis is based upon the study of the scaling of both the spreading and the entropy of the diffusion generated by the fluctuations of…

Statistical Mechanics · Physics 2009-11-10 Nicola Scafetta , Bruce J. West

We present the analysis of time-resolved spectroscopy of the pulsating sdB star PG1605+072. From our main observing run of 16 nights we have detected velocity variations at 5 frequencies that correspond to those found in photometry. Based…

Astrophysics · Physics 2009-11-07 S. J. O'Toole , T. R. Bedding , H. Kjeldsen , T. H. Dall , D. Stello

This article reviews some of the leading results obtained in solar dynamo physics by using temporal oscillator models as a tool to interpret observational data and dynamo model predictions. We discuss how solar observational data such as…

Solar and Stellar Astrophysics · Physics 2014-07-21 Ilídio Lopes , Dário Passos , Melinda Nagy , Kristof Petrovay

We establish several new stylised facts concerning the intra-day seasonalities of stock dynamics. Beyond the well known U-shaped pattern of the volatility, we find that the average correlation between stocks increases throughout the day,…

Statistical Finance · Quantitative Finance 2013-01-29 Romain Allez , Jean-Philippe Bouchaud

Signals from radio pulsars show a wavelength-dependent delay due to dispersion in the interstellar plasma. At a typical observing wavelength, this delay can vary by tens of microseconds on five-year time scales, far in excess of signals of…

Local-box hydrodynamical model atmospheres provide statistical information about the spatial dependence, as well as temporal evolution, of a star's emergent radiation field. Here, we consider late-type stellar atmospheres for which temporal…

Astrophysics · Physics 2009-11-11 Hans-G. Ludwig

The Sun affects the Earth's physical phenomena in multiple ways, in particular the material in interplanetary space comes from coronal expansion in the form of inhomogeneous plasma flow (solar wind), which is the primary source of the…

Solar and Stellar Astrophysics · Physics 2015-05-18 Lijia Liu , Xizhen Zhang , Jianbin Li , P. K. Manoharan , Zhiyong Liu , Bo Peng

Young stars exhibit short-term photometric variability caused by mass accretion events from circumstellar disks, the presence of dusty warps within the inner disks, starspots that rotate across the stellar surfaces, and flares. Long-term…

A variable speed of light (VSL) cosmology is described in which the causal mechanism of generating primordial perturbations is achieved by varying the speed of light in a primordial epoch. This yields an alternative to inflation for…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-21 J. W. Moffat

This paper describes some interesting properties of waves in, and oscillations of, the interstellar medium in the direction normal to the plane of the Galaxy. Our purpose is to examine possible reasons for four observed phenomena: the…

Astrophysics · Physics 2009-10-31 Michael A. Walters , Donald P. cox

We consider cosmological perturbations caused by modulated inflaton velocity. During inflation, the inflaton motion is damped and the velocity is determined by the parameters such as couplings or masses that may depend on light…

High Energy Physics - Phenomenology · Physics 2009-02-02 Tomohiro Matsuda

We investigate the variability properties of main sequence stars in the first month of Kepler data, using a new astrophysically robust systematics correction, and find that 60% of stars are more variable then the active Sun. We define low…

Solar and Stellar Astrophysics · Physics 2013-10-24 Amy McQuillan , Suzanne Aigrain , Stephen Roberts

Meteorological data have been used to calculate refractive index fluctuations - the indicator of optical instability of the Earth's atmosphere. The calculations were made for standard pressure levels of the atmosphere in winter and summer.…

Instrumentation and Methods for Astrophysics · Physics 2011-01-21 Pavel G. Kovadlo , Olga S. Kochetkova