detection and study of supernovae with the 4m international liquid mirror telescope
DESCRIPTION
Detection and study of supernovae with the 4m International Liquid Mirror Telescope. BRAJESH KUMAR University of Liège, Belgium ARIES, Nainital, India. OUTLINE:. HISTORY BASIC CONCEPTS OF LMTs ILMT Introduction - PowerPoint PPT PresentationTRANSCRIPT
Detection and study of supernovae with the 4m International Liquid Mirror Telescope
BRAJESH KUMAR
University of Liège, Belgium
ARIES, Nainital, India
OUTLINE:HISTORYBASIC CONCEPTS OF LMTsILMT Introduction Science with ILMTSUPERNOVAE STUDY WITH
ILMTCONCLUSIONS
History of Liquid MirrorsFirst concept - Ernesto Capocci - 1850
First working laboratory LMT- 0.35 m Henry Skey- 1872 Dunedin Observatory, New Zealand
Robert Wood – 1909 John Hopkins University
Ermanno Borra & Paul Hickson- 1982 Laval University, Canada University of British Columbia,
Canada
y
x
xAc
g g g g g g
Ac Ac Ac Ac Ac
AA A A A A
Basic concepts of Liquid Mirrors:
Basic Concepts of Liquid Mirrors: Parabola : ideal optical system
Constant gravity (g) + Centrifugal Acceleration (²x)
Parabolic surface Why ? Surface Acceleration
gx
dxdy 2
tan fx
gxy
42
222
)2( 2gf
Liquids as mirror: Mercury, Gallium, Rubidium, CesiumMercury: It is liquid above -38.8˚C Reflectivity : 79% - 90% (3100 –
13000 ) Inexpensive Surface oxide layer prevents toxic
mercury vapors
Basic concepts of Liquid Mirrors:
0A
0A
Basic concepts of Liquid Mirrors Detector : CCD camera Time Delay Integration for zenithal telescopes:
• Tracking by electronically stepping the charges on the CCD
• Rate of transfer of charges between rows of CCD equal to sidereal rate
INTERNATIONAL LIQUID MIRROR TELECOPE Mirror diameter: 4mRotation period: 8 secFocal length: 8m – f/2Resolution: 0.6’’FOV: 24’x24’CCD: 4096x4096 pixels (15 m pixels)Filters: i’ , r’ , g’ (i’ permanently mounted) (i’=762.5 nm, r’=623.1 nm, g’=477 nm)Working temperature: -20˚C to 25˚CLife expectancy: 5 years
(Surdej et al. 2006)
9
Structure
Mirror
CCD Camera Corrector
Alignment mechanisms
Upper end
Vertical fixed structure focal length = 8 m
Air bearing and motor
Carbon fiber container (d=4m)
DIFFERENT PARTS OF ILMT
SPIN CASTING OF ILMT:Mixing of polyurethane
Pouring of polyurethane Final mirror shape
Taking parabolic shape
INTERNATIONAL LIQUID MIRROR TELESCOPECollaborating countries: Belgium, Canada, IndiaLocation : Devsthal, India 79⁰ 41’ East, 29⁰ 23’ N Altitude : ~ 2400 mExpected first light: September 2010 Devsthal
Nainital
SCIENCE WITH ILMT
Supernovae Variable objectsGravitational lensesStudy of galaxiesData base for follow up
SNe search and related problems
Local SNe are rareSample of galaxiesFrequency and magnitude of observationsInstruments/techniques The answer is ILMT
SUPERNOVAE STUDY WITH ILMT
SUPERNOVAE STUDY WITH ILMT
ILMT: sky strip=24ˊ galactic latitude~ 30˚ total observed
area=146 sq. deg. extragalactic region=72
sq. deg.
Integration time single pass
t=1.37 * *n w/f cos(lat) n=number of pixels w= width of pixel f= focal length lat=latitude of the
observatory
ILMT integration time ~ 100 seconds Limiting magnitude (100 seconds)=22.5 Co-addition will increase the limiting
magnitude
10 2
Supernovae detection : (0.3<z<0.5) Type Ia 1000 Core collapse 3600 SNe Ib/c 1080 Bright SN Ib/c 216 (Pain et al. 1996, Dahlen et al.
2004 , Cappellaro et al. 1999, Strogler et
al. 2004)
SUPERNOVAE STUDY WITH ILMT
O-IR telescopes, additional benefit
For any transient event recognized by ILMT, the 3.6m telescope will be used for further photometric and spectroscopic studies.
CONCLUSIONSILMT will scan 24’x24’ of sky and detect many
stellar objects. It will provide unique data base for large
conventional telescopes.Thousands of supernovae will be detected ( both
type Ia and core collapse) using ILMT.More light on classification of Supernovae.About GRB supernovae relation
THANKS
http://www.aeos.ulg.ac.be/LMT