Imaging and spectroscopy with FORS 1 in the field of Q 0307 − 0015 ? , ? ?
نویسنده
چکیده
We present VLT–observations of a recently detected galaxy cluster candidate in the field of the radio–quiet quasar Q 0307−0015. R–band images and multi–object spectra (MOS) have been obtained during the commissioning phase II of FORS1 in December 1998. The presumed central cluster galaxy shows the typical spectrum and surface brightness profile of an early–type galaxy and has a redshift of z=0.396. We measured the redshift of 20 galaxies in the 6.′8 × 6.′8 field and found further 11 galaxies with similar redshift implying that we see a galaxy cluster at intermediate z. We estimate the cluster richness to be comparable with Abell class 0–1. The cluster is not physically associated with Q 0307−0015 having a redshift of z=0.770. This was to be expected considering the projected distance of ≈5′on the sky. A closer look at the immediate sourrounding of the QSO shows that Q 0307−0015 seems to reside in an unspectacular environment. Neither a definite close companion candidate nor any excess population of faint galaxies can be seen. This is consistent with the finding at low redshift that most radio– quiet QSOs reside in poorer environments than their radio–loud counterparts.
منابع مشابه
Design and fabrication of a high-Q near-field probe for subsurface crack detection
Non-destructive detection and evaluation of invisible cracks in metal structures is an important matter in several critical environments including ground transportation, air transportation and power plants. In this paper, a high-Q near-field Microwave probe is designed and fabricated using defected ground structures for surface and subsurface crack detection in metal structures. For this purpos...
متن کاملEarly Results of the Eso Vlt
The results of the FORS and ISAAC Science Verification of the FORS and ISAAC instruments at the VLT ANTU/UT1 are described. The following observations have been carried out: 1) the Cluster Deep Field MS1008.1-1224 2) the Antlia dwarf spheroidal Galaxy 3) multiple Object Spectroscopy of Lyman break galaxies in the AXAF and Hubble Deep Field South 4) ISAAC IR Spectroscopy of a gravitationally mag...
متن کاملRelationship between Baseline ECG Abnormalities and Quantitative Perfusion Parameters of Myocardial Perfusion Findings
Background: Coronary Artery Disease (CAD) is one of the major causes of mortality in most countries. Electrocardiography (ECG) and myocardial perfusion imaging (MPI) are non-invasive disgnostic tests for CAD. Finding a relationship between abnormal findings in the baseline ECG and MPI findings can be helpful in better diagnosis of CAD. Materials and Methods: The present study examined ECG of pa...
متن کاملSpurious lung perfusion ventilation defect on planar ventilation-perfusion scan detected by SPECT imaging
Pulmonary embolism (PE) is a preventable cause of morbidity and mortality which needs prompt recognition. Ventilation-perfusion (V/Q) scan is a well-established diagnostic test for evaluation of suspected PE. We report a 32-year-old woman with history of rheumatologic disease and acute dyspnea, who was referred for V/Q scintigraphy. The planar images revealed multiple mismatched defects through...
متن کاملHEAT TREATMENT AND OPTICAL SPECTROSCOPY OF CR4+:GGG FOR PASSIVELY Q-SWITCHING ND:GARNET LASERS
High quality GGG:Cr,Ca crystal for passive Q-switching Nd:garnet lasers has been grown by the Czochralski method. Thermal treatment of GGG crystals co-doped with Cr4+ and Ca2+ at different temperatures is investigated. The absorption spectra were resolved into different peaks, of modified Gaussian line-shape. Transition from octahedral sites to tetrahedral ones is thermally activated. An...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1999