Related papers: Microwave response to sunspot oscillations

We report the detection of multi-periodic oscillations of the cool evolved star alpha Hya (HD 81797, K3II-III). Two-hundred and forty-three high-resolution spectra (R=48,000) of this star have been obtained in March and April 2005 with…

The radio transient ASKAP J173608.2-321735, at the position (l,b)= (356.0872,-0.0390), was serendipitously observed by The HI/OH/Recombination Line Survey of the Galactic Center (THOR-GC) at three epochs in March 2020, April 2020 and…

Fast radio bursts (FRBs) are extra-galactic sources with unknown physical mechanisms. They emit millisecond-duration radio pulses with isotropic equivalent energy of $10^{36}\sim10^{41}$ ergs. This corresponds to a brightness temperature of…

We present the first high spectral resolution observations of Orion KL in the frequency ranges 1573.4 - 1702.8 GHz (band 6b) and 1788.4 - 1906.8 GHz (band 7b) obtained using the HIFI instrument on board the Herschel Space Observatory. We…

Solar type III radio bursts are excited by electron beams propagating outward from the Sun. The flux of type III radio burst has a time profile of rising and decay phase at a given frequency, which has been actively studied since 1970s.…

We investigate the emission of sub-millimetre-wave radiation from galaxies in a 165 square arcminute region surrounding the Hubble Deep Field North. The data were obtained from dedicated observing runs from our group and others using the…

Some repeating fast radio burst (FRB) sources exhibit complex polarization behaviors, including frequency-dependent depolarization, variation of rotation measure (RM), and oscillating spectral structures of polarized components. Very…

Powerful relativistic jets are one of the ubiquitous features of accreting black holes in all scales. GRS 1915+105 is a well-known fast-spinning black-hole X-ray binary with a relativistic jet, termed as a ``microquasar'', as indicated by…

Solar radio bursts exhibit complex fine structures that reveal intricate coronal plasma dynamics. Here, we report detection of spike-like repeating burst pairs, characterized by two short-lived (0.1-2 s), narrowband components separated by…

Very Large Array observations of the Galactic Center at 7 mm have produced an image of the 30 arcseconds surrounding Sgr A* with a resolution of 82x42 milliarcseconds (mas). A comparison with IR images taken simultaneously with the Very…

Several sources of repeating coherent bursts of radio emission with periods of many minutes have now been reported in the literature. These "ultra-long period" (ULP) sources have no clear multi-wavelength counterparts and challenge…

We present images at 6 and 14 GHz of Source I in Orion-KL. At higher frequencies, from 43 to 340 GHz, images of this source are dominated by thermal emission from dust in a 100 AU diameter circumstellar disk, but at 6 and 14 GHz the…

We present serendipitous detections of radio sources at 28.5 GHz (1 cm), which resulted from our program to image thermal Sunyaev-Zeldovich (SZ) effect in 56 galaxy clusters. We find 64 radio sources with fluxes down to 0.4 mJy, and within…

High-resolution infrared spectroscopy in the 2.3-4.6 micron region is reported for the peculiar A supergiant, single-lined spectroscopic binary HR 4049. Lines from the CO fundamental and first overtone, OH fundamental, and several H2O…

While analyzing decades of very long baseline interferometry (VLBI) data, we detected the secular aberration drift of the extragalatic radio source proper motions caused by the rotation of the Solar System barycenter around the Galactic…

We have compiled a sample of 234 ultra-steep-spectrum(USS)-selected radio sources in order to find high-redshift radio galaxies (HzRGs). The sample is in the southern sky at -40 deg < DEC < -30 deg which is the overlap region of the 408-MHz…

The origin of the large-amplitude, quasi-periodic X-ray flux variations in several classes of the Galactic microquasar GRS~1915+105 remains unresolved. We address this issue through flux-resolved, broadband (0.8-20 keV) spectral modelling…

Three types of observations: the daily values of the solar radio flux at 7 frequencies, the daily international sunspot number and the daily Stanford mean solar magnetic field were processed in order to find all the periodicities hidden in…

SGR 1833-0832 was discovered on 2010 March 19 thanks to the Swift detection of a short hard X-ray burst and follow-up X-ray observations. Since then, it was repeatedly observed with Swift, Rossi X-ray Timing Explorer, and XMM-Newton. Using…

One of the most commonly observed solar radio sources in the metric and decametric wavelengths is the solar noise storm. These are generally associated with active regions and are believed to be powered by the plasma emission mechanism.…