相关论文: Night sky at the Indian Astronomical Observatory d…
We report the results of a search for molecular oxygen (O2) toward the Orion Bar, a prominent photodissociation region at the southern edge of the HII region created by the luminous Trapezium stars. We observed the spectral region around…
Photometric redshifts are studied with a template approach using data from HDF-N and -S . The problem of aliasing in photometric redshift estimates is investigated in some detail and found not to be a significant problem if at least four…
We present late-epoch optical photometry (BVRI) of seven normal/super-luminous Type Ia supernovae: SN 2000E, SN 2000ce, SN 2000cx, SN 2001C, SN 2001V, SN 2001bg, SN 2001dp. The photometry of these objects was obtained using a template…
We present results using 2-D spectral imagery and photometry obtained with the Hubble Space Telescope (HST) for the starburst H II region, NGC 604, in nearby galaxy M33. The spectral imagery was acquired with the Space Telescope Imaging…
We present the new constraints on the cosmic optical background (COB) obtained from an analysis of the Pioneer 10/11 Imaging Photopolarimeter (IPP) data. After careful examination of data quality, the usable measurements free from the…
Understanding the effects of dust extinction is important to properly interpret observations. The optical total-to-selective extinction ratio, Rv = Av/E(B-V), is widely used to describe extinction variations in ultraviolet and optical…
We present a spectral variability study of the ultraluminous X-ray source NGC 4490 ULX-8 based on 14 Chandra, 6 XMM-Newton and 19 Swift-XRT observations obtained between 2000 and 2024. The X-ray spectra are modelled using absorbed power-law…
A sample of 109 type Ia supernovae (SNe Ia) with recession velocity < 30,000 km s^{-1}, is compiled from published SNe Ia light curves to explore the expansion rate of the local Universe. Based on the color parameter delta C_{12} and the…
We have used observations taken under the FUSE S405/S505 channel realignment program to explore the diffuse FUV (1000 - 1200 \AA) radiation field. Of the 71 independent locations in that program, we have observed a diffuse signal in 32,…
We present integral field spectroscopy of two selected zones in the Orion Nebula obtained with the Potsdam Multi-Aperture Spectrophotometer (PMAS), covering the optical spectral range from 3500 to 7200 A and with a spatial resolution of 1".…
We report the results of a survey for HI 21-cm absorption at redshifts of z > 2.6 in a new sample of radio sources with the Green Bank and Giant Metrewave Radio Telescopes. From a total of 25 targets, we report zero detections in the 16 for…
We present a new atmospheric extinction curve for Mauna Kea spanning 3200--9700 \AA. It is the most comprehensive to date, being based on some 4285 standard star spectra obtained on 478 nights spread over a period of 7 years obtained by the…
We report a high-resolution (R=3000-4000) spectroscopic observation of the DA white dwarf G191-B2B in the extreme ultraviolet band 220-245 A. A low- density ionised He component is clearly present along the line-of-sight, which if…
Baryon Acoustic Oscillations (BAO) provide a robust standard ruler for observational cosmology, enabling precise constraints on the expansion history of the Universe. We present a weakly model-dependent measurement of the BAO angular scale…
Interstellar extinction in ultraviolet is the most severe in comparison with optical and infrared wavebands and a precise determination plays an important role in correctly recovering the ultraviolet brightness and colors of objects. By…
The region surrounding the Llano de Chajnantor, a high altitude plateau in the Atacama Desert in northern Chile, has caught the attention of the astronomical community for its potential as an observatory site. Combining high elevation and…
We report on the results of our monitoring program of the remnant of SN 1987A with the Advanced CCD Imaging Spectrometer (ACIS) on board the {\it Chandra X-ray Observatory}. Two new observations have been performed in AO2, bringing the…
We present the first detection of the baryon acoustic oscillations (BAO) signal obtained using unblinded data collected during the initial two months of operations of the Stage-IV ground-based Dark Energy Spectroscopic Instrument (DESI).…
The summit of the Antarctic plateau, Dome A, is proving to be an excellent site for optical, NIR, and THz astronomical observations. GATTINI was a wide-field camera installed on the PLATO instrument module as part of the Chinese-led…
The clarity of nights is the major factor that should be carefully considered for optical/infrared astronomical observatories in site-testing campaigns. Cloud coverage is directly related to the amount of time available for scientific…