LISA spectrograph Long slit Intermediate resolution Spectrograph for Astronomy Performances and...

LISA spectrographLong slit Intermediate resolution Spectrograph for Astronomy

Performances and application

Christian Buil

Active Spectroscopy in AstronomyEssen – 7 May 2011

1Essen - 7 May 2011

Spectrograph resolution categories ( R)

High resolution Lhires R = 16000

eShel R = 11000

Medium resolution(or intermediate)

LISA R = 500 to 1000

Low resolutionStar Analyser R = 100 to 200

2Essen - 7 May 2011

Spectral resolution (R) and luminosity (L) : a complementary effortR x L = constant

Planetary nebulae NGC 2392 – 15 x 30 seconds

Faint object spectroscopyThe example of Star Analyser : very low resolution, very high luminosity

3Essen - 7 May 2011

But do not mystake luminosity and detectivity !

Faint object spectroscopy

One limitation of slitless spectroscopy : sky background pollution

The symbiotic star V1016 Cyg

Another limitation of SA : optical aberration

Chromatic coma : a source of detectivity degradation (bad capacity to concentrate energy)

Grism improvement

4Essen - 7 May 2011

Faint object spectroscopy

The importance of an entrance slit

Large slit

Narrow slit

The sky background level if proportionnal to the slit wideThe backgroung photon noise is proportionnal to the square root of slit wide

5Essen - 7 May 2011

The LISA concept (1/2)

- Ajustable entrance slit by step (from 15 microns to 100 microns) (capacity to optimise spectral resolution to a specific target)

- Fast input beam : up to f/5 input i.e. high luminosity spectrograph (reduce potential guidance problem because shorter focal length, capture of faint surface objet like galaxies, comets, …

- Optimized spectral dispersion to modern camera (2 A / pixel sampling on a popular KAF8300 CCD ship)

- Balance between power resolution capacity and scientific interest (R = 500 to 1000 typically) – Sodium doublet is just separated with a 23 microns slit

Mg I,2,3 NaDA, D2 Halpha

2D spectrum of moon surface

6Essen - 7 May 2011

- Wide spectral range in one shot : 3950 A – 7200 A (+ IR option)

- Integrated calibration system (neon lamp + tungsten lamp) : easy to use and standard pipeline processing. Possibility to fully automatize acquisition.

- Compact and moderate weigth : adaptable on small refractor and refractor.

- Low cost : large diffusion if possible!

The LISA concept (2/2)

7Essen - 7 May 2011

Optical design

Internal grandissement G = 0,603

For example: if the telescope focal / diameter ratio is 6, the final F/D is 6 x 0,603 = 3,6(LISA is equivalent to a focal reducer).

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Mechanical design

9Essen - 7 May 2011

Mechanical design

Calibration unit Ajustable grating angle

10Essen - 7 May 2011

Pointing and guidance system

High reflectivity slitVery constant edge

High quality slit image on the guidance camera(here M104 galaxy with a Watec 120N)


LISA on a Celestron 11 telescope


Calibration module (spectral calibration and flat-field)

Electromagnetic system – 12 V power – Remote operation possible

Essen - 7 May 2011 13

Interfaces

Optimal input focal ratio f/5 to f/7A fast Newton telescope is ideal (achromatism)

For SC Telescope : focal reducer(here a Baader Alan Gee - final ratio f/6.8)

Fast adaptation for CCD camera and DSRL


Essen - 7 May 2011 15

Example of setup with Atik CCD cameras

Atik 314L for spectra acquistion (1390 x 1040 x 6.45 µm pixel size)Readout noise : 4.5 e-, Camera gain : 0.250 e-/ADU, typical quantum efficiency @ 656 nm : 55%

Atik Titan for pointing and guiding functions(faint object identification capability + rudimentary photometry measure on the targets)

Low cost solution for LISA, low mass on the telescope, high performances

Amovible entrance slitHigh precision chromium serigraphy

Slit 23 microns – R = 1100W = 2,5 arcsec on C11 f/6.8

Slit 50 microns – R = 600W = 5.4 arcsec on C11 f/6.8

15 – 19 – 23 – 32 microns (option 50 – 75 – 100 microns + 19 microns hole)


Automatised processingRlhires application


Automatic spectral calibration by using observed type A, B or G star spectra and internal neon lamp spectrum

Fit dispersion law with a 3e order polynomial function (typical RMS error : 0.3 to 0.4 A) 18Essen - 7 May 2011

Many tools available : computation of heliocentric velocity, H2O removal, atmopsheric transmission, spectra database, …. French/english interface


Slit 23 µmR = 1100

Slit 50 µmR = 600

Slit 100 µmR = 290

D = 12.8 cmF/D = 8

12.5 13.1 13.4

D = 28 cmF/D = 6.8

13.6 14.6 15.0

D = 35 cmF/D = 6.8

13.9 14.9 15.4

D = 50 cmF/D = 6.0

14.4 15.5 16.2

D = 100 cmF/D = 6.0

15.2 16.3 17.2

Slit 23 µmR = 1100

Slit 50 µmR = 600

Slit 100 µmR = 290

D = 12.8 cmF/D = 8

13.1 13.6 13.9

D = 28 cmF/D = 6.8

14.5 15.2 15.6

D = 35 cmF/D = 6.8

14.8 15.6 16.1

D = 50 cmF/D = 6.0

15.3 16.3 16.9

D = 100 cmF/D = 6.0

16.1 17.3 18.2

Integration time : 1 hour (6 x 600 sec)Signal to noise ratio = 10 (@ Halpha)

Type A0V star – Seeing = 3 arcsecCCD KAF-8300 (Binning 1 x1)

Limit magnitude

Altitude 0 m - Suburban Altitude 3000 m – Dark sky


Slit 50 µmR = 600

Slit 100 µmR = 280

D = 12.8 cmF/D = 8

13.7 14.0

D = 28 cmF/D = 6.8

15.4 15.8

D = 35 cmF/D = 6.8

15.8 16.2

D = 50 cmF/D = 6.0

16.4 17.0

D = 100 cmF/D = 6.0

17.4 18.3

Slit 50 µmR = 600

Slit 100 µmR = 280

D = 12.8 cmF/D = 8

14.2 14.5

D = 28 cmF/D = 6.8

15.8 16.2

D = 35 cmF/D = 6.8

16.2 16.7

D = 50 cmF/D = 6.0

16.9 17.5

D = 100 cmF/D = 6.0

17.8 18.7

Integration time : 1 hour (6 x 600 sec)Signal to noise ratio = 10 (@ Halpha)

Type A0V star – Seeing = 3 arcsecAltitude 3000 m – Dark sky

Limit magnitude (function of detector type)

CCD KAF-8300 (Binning 2 x2) CCD KAF-3200 (Binning 2 x2)

3 hours integration (18 x 600 sec) – Slit 50 µm – D = 28 cm F/D = 6.8 M = 16.1 (KAF-8300)M = 16.5 (KAF-3200)M = 16.6 (ICX424AL)


Slit 50 µmR = 600

Slit 100 µmR = 280

D = 12.8 cmF/D = 8

14.3 14.7

D = 28 cmF/D = 6.8

16.0 16.3

D = 35 cmF/D = 6.8

16.4 16.8

D = 50 cmF/D = 6.0

17.1 17.6

D = 100 cmF/D = 6.0

18.1 19.0

CCD ICX285AL (Binning 2 x2)

Observation with LISA spectrograph


Star Analyser

Typical aspect of LISA 2D spectraSymbiotic star V1016 Cyg

2D spectrum before sky removal (23 µm slit)

2D spectrum after sky substraction


Symbiotic star V1016 Cyg (V = 11.2) : lines identification


First step : observation of normal stars (1/2)


First step : observation of normal stars (2/2)


Survey of know Be Star + and detection of new Be star

Beta Lyrae (Shelyak) – 15 x 30 s

Rapid scan of B and A star for Halpha emission signature (5-10 minutes exposure)(list of nearly 1000 stars – magnitude < 10)


Faint Be stars observation (BeSS)

V = 6.09 – 9 x 120 s V = 4.74 – 8 x 60 s

V = 8.62 – 6 x 300 s (new BeSS entry) V = 8.63 – 7 x 300 s (new BeSS entry) 28Essen - 7 May 2011

Survey of cataclysmic(novae like)

SS Cyg outburst (V = 8.7) – April 4.1, 2011


List of cataclysmic star (François Teyssier)

…


Outburst of cataclysmic V694 MonHigh velocity wind – Fast evolution


V694 Mon – Visible + IR capacity of LISA spectrograph


Recurent nova T Pyxidis : day to day monitoring of profile evolution


T Pyxidis 2D spectrum

6 arcsec refractionat 12 degree elevation

Paralactic angle

Observation at very low angular elevation : associated problemT Pyxidis declinaison = -32 degrees

Horizon


Nova Sagittarii 2011 #2 (V5588 Sgr)V = 13.2


Eruption of Herbig Ae/Be star Z CMa

Vis + IR spectrum

Detail of IR spectrum


MIRA starR Leo at V = 8.5

Wide band spectrum


HD 56925 in NGC 2359 nebula

Wolf-Rayet star HD 56925WR 7 – V = 11.7


R Mon in NGC 2261 nebula3 x 600 s @ R = 1000

Messier 1 (Crab nebulae) - 5 x 600 s @ R = 600


SUPERNOVASN 2011ae in MCG-3-30-19


SUPERNOVASN 2011by in NGC 3979


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Messier 104Sombrero galaxy

Audela autoguiding

2D spectrum

Na rest = 5892.9 A - Na observed = 5916.9 A – z = (5916.9 – 5892.9) / 5892.9 = 0.0041 (17 Mpc)

NGC 4151

NGC 4051

Active galaxies (Seyfert)


McDonald 2,1 mK. Thompson AJ, 395, 404,417, 1992

Quasar 3C273

Observed Halpha at 7584 Az = (7584 - 6563)/6563 = 0.155(official z = 0.158)


LISA infrared version

Quasar Mrk 205 observation(V = 15.5)


Observed z = 0.0710 (official value z = 0.0705)

Quasar Mrk 2057 x 600 sec. – 50 µm slit


Thank you


LISA spectrograph Long slit Intermediate resolution Spectrograph for Astronomy Performances and...

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