Overview
- A Spectroscopic Survey of Intermediate Redshift QSOs(2.1<z<2.5)
- Abundance ratios of Extremely Metal Poor Stars from theHamburg-ESO Survey
- Chemical Abundances in LMC Clusters in a Wide Age Range
- Supernova 1987
A Spectroscopic Surveyof Intermediate Redshift QSOs
These observations are meant to be the first step towards a public surveyof QSO Absorbers which aims at creating a large and homogeneous datasetto allow the study of the intergalactic medium and halos of high-zgalaxies at z = 0-3.
* thermal history of the IGM, intensity and shape of the UV background
* Redshift evolution of matter distribution
* Kinematics and metal-enrichment in the IGM and halos of high-z galaxies
The 3 highlighted QSOs were observed with a slit of 0.8" (red)and 0.9" (blue) when the seeing was good, and 1" when the seeing was mediocre(R=50000-43000). A combination of the two Dichroic settings Dic 1(B346nm+ R580nm) and Dic2 (B347nm + R860nm) provided the whole spectralrange 300nm-1000nm. Depending on the seeing conditions, the binning ofthe CCD was 2x2 or 2x1, and exposure times were between 1h and 1h30.
Q 1101-264:
Dic 1 (B346nm + R580mn) = 6h00
Dic 2 (B437nm + R860mn) = 6h00
HE 1122-1648
Dic 1 (B346nm + R580mn) = 7h20
Dic 2 (B437nm + R860mn) = 6h30 (1h00and 2x1h30 are low counts because of poor seeing)
HE 1347-2457
Dic 2 (B437nm + R860mn) = 4h00
The following S/N arise from a quick-look analysis of the dataobtained for Q1101-264 and HE1122-1648. These two QSOs have similarflux of 2 x 10^-15 erg s^-1 cm^-2 A^-1 at 3200 A (from IUE, HST and optical data). No binning/smoothing has been applied for the estimate ofthe S/N which is given per spectral pixel of the extracted spectra.
Lambda S/N
3150 15
3400 50
3800-6000 60-80
Abundance Ratiosof Extremely Metal Poor stars
The known objects closest to pristine, unevolvedmatter are the Extremely Metal-Poor Stars in our Milky-Way, which havemetallicities less than 1/1000th of solar.The detailed chemical contentof these stars yields insight on early Galactic evolution and nucleosynthesis:* primordial light elements abundances (Li,Be)
* elemental yields of early SNII and their massfunction
* nucleosynthetic products of first AGBs
* efficiency of mixing process in the early Galaxy
The S/N stated is an aproximate value perspectral pixel of the extracted spectra, around 520nm
HE 1353-2735*
Dic 2 (B470nm + R785nm) 2x1h30 S/N 50,50
HE 1303-2708
Dic 2 (B470nm + R785nm) 2x1h30 +1h** +0h45 S/N 62,tbd,tbd,tbd
Notes:
* thisstar turned out to be most likely a double-lined binary
** the blue image ofthis exposure was lost because of a technical problem
n addition to these new metal-poor candidates,G64-12, a well-known extremely metal poor star was observed at very highS/N to provide the community with a "template spectrum" of a verymetal poor star (test of models, ...), all the way to the UV.
The observations were done with a 0.8" slit (R=60,000)and 2 Dichroic modes (Dic1 B346nm + R580nm and Dic1 B346 + R860nm) givinga total coverage : 300nm-390nm +480nm-1000nm.
G 64-12
Dic 1 (B346nm + R580nm) 2x1h30 S/N 100,115 @335nm
350,370@510nm
Dic 1 (B346nm + R860nm) 2x1h30 S/N 85,105 @335nm
270,280@700nm
Chemical Abundancesin LMC Clusters in a Wide Age Range
The star formation and chemical enrichement historyof the Large Magellanic Clouds can be investigated using stellar clustersin a wide age range as tracers. In addition, the knowledge of the chemicalcomposition of stars in stellar clusters in the MCs can be used as stellarphysics tools : ages of the clusters, evolutionary tracks at low metallicities,...9 Giants were observed in the 4 highlighted clusterswith the R580nm setting and a slit of 1.0" to 1.2" (depending onseeing ) corresponding to R=40,000 to 45,000, and giving a spectral coverage:480nm-680nm.
The S/N stated is an approximate valueper spectral pixel of the extracted spectra, around 600nm
NGC 1866 (IdentificationBrocato et al. 1989)
R580 1h30 star444 S/N 70
R580 1h00 star1653 S/N 80
R580 2x1h00 star 867 S/N 23,25
NGC 1978(Identification Loyd & Evans 1980)
R580 2x1h15 star LE8 S/N 48,48
R580 2x1h15 star LE9 S/N 47,42
Dic 2 (B437nm + R860nm) 2 x1h15 star LE9
ESO 121 (Identification Mateo 1986)
R580 2x1h30 star M313 S/N 23,28
R580 2x1h15 star M167 S/N 40,40
NGC 2210 (IdentificationBrocato et al. 1996)
R580 1h40 star4364 S/N 50 + star 110 on the same slit
R580 1h30 star4793 S/N 50
Supernovae 1987a
2 spectra of SN87a were obtained with the R580nmand Dic1 (B346nm + R580nm) settings providing a spectral coverage 300nm-390nm+ 480nm-680nm .SN87a
R580 30mn
Dic1 1h00