Search Publications
The first optical light from the supernova remnant G182.4+4.3 located in the Galactic anticentre region
Sezer, A.; Gök, F.; Aktekin, E.
We report the discovery of optical filamentary and diffuse emission from G182.4+4.3 using the 1.5-m Russian-Turkish telescope. We present the optical CCD images obtained with the Hα filter, revealing the presence of mainly filamentary structure to the north-west and filamentary and diffuse structure in the centre, south and north regions of the re…
Ion-ion charge exchange and X-rays from the winds of hot stars
Pollock, A. M. T.
Charge exchange occurs between charged ions with enough energy to overcome Coulomb repulsion, a condition satisfied for collisions at velocities like those of the winds driven from hot stars by radiation pressure. X-ray line ratios in some hot stars are inconsistent with those expected from thermal plasmas excited by electron impact. Ion-ion inter…
Ca II Transient Brightenings Associated with Canceling Magnetic Features
Chae, Jongchul; Park, Soyoung
We analyzed transient Ca II H brightening associated with small-scale canceling magnetic features (CMFs) in the quiet Sun near disk center using Ca II H filter images and Na D1 magnetograms of Hinode/SOT. We found that in most Ca II brightening events related to CMFs the Ca II H intensity peaks after the magnetic flux cancellation. More…
The effect of protons on the performance of second generation Swept Charge Devices
Gow, Jason P. D.; Holland, Andrew D.; Pool, Peter J. +1 more
The e2v technologies Swept Charge Device (SCD) was developed as a large area detector for X-ray Fluorescence (XRF) analysis, achieving near Fano-limited spectroscopy at -15 °C. The SCD was flown in the XRF instruments onboard the European Space Agency's SMART-1 and the Indian Space Research Organisation's Chandrayaan-1 lunar missions. The second g…
Star formation in the starburst cluster in NGC 3603
Ventura, Paolo; Valenti, Elena; Pang, Xiaoying +7 more
We have used new, deep, visible and near infrared observations of the compact starburst cluster in the giant HII region NGC 3603 and its surroundings with the WFC3 on HST and HAWK-I on the VLT to study in detail the physical properties of its intermediate mass (∼1–3 M⊙) stellar population. We show that after correction for differential …
Cl 1103.7-1245 at z = 0.96: the highest redshift galaxy cluster in the EDisCS survey
Fritz, J.; Vulcani, B.; Milvang-Jensen, B. +6 more
We present new spectroscopic observations in a field containing the highest redshift cluster of the ESO Distant Cluster Survey (EDisCS). We measure galaxy redshifts and determine the velocity dispersions of the galaxy structures located in this field. Together with the main cluster Cl 1103.7-1245 (z = 0.9580; σclus = 522 ± 111 km s…
Ultraviolet absorption observations of intermediate-velocity cloud gas detected towards the M 15 globular cluster
Lallement, R.; Welsh, B. Y.; Wheatley, J.
Aims: We present medium resolution ultraviolet interstellar absorption measurements recorded with the HST-COS and FUSE spectrographs towards two post-AGB stars (K 559 K 648) located within the M 15 globular cluster (l ~ 65°, b ~ -27°). By sampling interstellar gas over the 10.4 kpc sight-line towards M 15 we wish to reveal spectral features t…
Stellar contents and star formation in the young cluster Stock 18
Pandey, J. C.; Sagar, Ram; Bhatt, Himali
We have carried out deep (V ∼ 21 mag) UBVRI photometric study of the star cluster Stock 18. These along with archival Infrared data have been used to derive the basic cluster parameters and also to study the star formation processes in and around the cluster region. The distance to the cluster is derived as 2.8 ± 0.2 kpc while its age is estimated…
Statistical Studies on Geomagnetically Induced Current Events Driven by Earth-directed Full Halo Coronal Mass Ejections
Lin, J.; Liu, C. M.; Wang, K. R. +1 more
Solar activities and eruptions can cause the power transmission system to be an abnormal condition,especially for an extra-long distance electric power transmission system.We analyzed the coronal mass ejection (CME) data from SOHO/LASCO (Solar and Heliospheric Observatory/Large Angle and Spectrometric Coronagraph),and the geomagnetically induced c…
The evolution of the X-ray emission of HH 2. Investigating heating and cooling processes
Schmitt, J. H. M. M.; Günther, H. M.; Schneider, P. C.
Young stellar objects often drive powerful bipolar outflows, which evolve on timescales of a few years. An increasing number of these outflows has been detected in X-rays implying the existence of million degree plasma almost co-spatial with the lower temperature gas observed in the optical and near-infrared. The details of the heating and cooling…