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User Manual

  Doc. Number:  ESO-323064
  Doc. Version:  2
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19 of 82

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3.2.1.2 Adaptive Optics

A technique to overcome the degrading e

ff

ects of atmospheric turbulence is real-time

compensation of the deformation of the WF by adaptive optics (AO, Figure 10).

Figure 10: Principle of Adaptive Optics. Note that in practice, and contrary to the this
schematic design, CRIRES has not dedicated tip-tilt mirror, but perform low- and high-order
correction with a single deformable mirror mounted on a tip-tilt stage (see Figure 12).

The wavefront sensor (WFS) measures WF distortions which are processed by a real-time
computer  (RTC).  The  RTC  controls  a  deformable  mirror  (DM)  to  compensate  the  WF
distortions.  The  DM  is  a  continuous  thin  plate  mirror  mounted  on  a  set  of  piezoelectric
actuators that push and pull on the back of the mirror.  Because of the significant reduction
in the WF distortions by continuous AO correction, it is possible to record near diffraction-
limited  images  with  exposure  times  that  are  significantly  longer  than  the  turbulence
coherence  time.  The  residual  error  from  the  WF  compensation  (WF  error)  directly
determines the quality of the formed image. One of the main parameters characterizing this
image quality is the Strehl ratio (SR), which corresponds to the amount of light contained in
the di

ff

raction-limited core relative to the total flux.

An AO system is a servo-loop system working in closed loop. The DM flattens the incoming
WF and the WFS measures the residual WF error. A commonly used WFS is the Shack-
Hartmann WFS, used for example in NACO. However, CRIRES, as well as other ESO
MACAO systems, relies on a curvature WFS: it is designed to measure the WF curvature
as opposed to the WF slope. This is achieved by comparing the irradiance distributions of
two planes placed behind and in front of the focal plane. In practice, a variable curvature
mirror (membrane) is placed in the telescope focus. By vibrating, inside and outside focus
blurred pupil images can be imaged on a detector array: in the case of CRIRES, a lenslet
array feeds avalanche photo-diodes (APDs). The modulation frequency of the membrane
corresponds to the temporal sampling frequency of the WFS. The di

ff

erence between the

inside and outside pupil image measures the local WF curvature.

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Содержание CRIRES+

Страница 1: ...i München www eso org Programme PIP Project WP CRIRES CRIRES User Manual Document Number ESO 323064 Document Version 2 Document Type Manual MAN Released On Document Classification Public Prepared by Valenti Elena Validated by Bristow Paul Approved by Dorn Reinhold Name Released by ESO PDM SYSTEM Digitally signed by Released by ESO PDM SYSTEM Date 2021 02 26 09 05 09 01 00 ...

Страница 2: ...e 2 of 82 Document Classification Public Authors Name Affiliation Elena Valenti ESO Anna Brucalassi INAF Florian Rodler ESO Change Record from previous Version Affected Section s Changes Reason Remarks All First version after on sky commissioning to be used for operation ...

Страница 3: ... Optic System MACAO 18 3 2 2 MACAO Hardware Description 20 3 2 3 The New Calibration Unit 23 3 2 4 The Spectro Polarimetry Unit SPU 28 4 INSTRUMENT PERFORMANCE 30 4 1 OVERVIEW 30 4 2 AO PERFORMANCE 30 4 3 DETECTOR CHARACTERISTIC 32 4 3 1 Dark and gain 33 4 3 2 Correcting for detectors non linearity 35 4 4 CHARACTERISTIC OF THE SPECTROGRAPH 35 4 4 1 Slit viewer camera field of view 35 4 4 2 Slit vi...

Страница 4: ...OR MODE OBSERVATIONS 55 6 3 OB PREPARATION 55 6 3 1 Target acquisition template 55 6 3 2 Science templates 61 6 3 3 Night time calibrations 66 6 3 4 OB Constraint set 69 6 3 5 Ephemeris 70 6 3 6 Finding Charts 70 6 3 7 README file 70 7 REFERENCE MATERIAL 72 7 1 CALIBRATION PLAN 72 7 2 WAVELENGTH SETTINGS 73 7 3 TEMPLATE SIGNATURE FILES 74 7 3 1 Acquisition TSF 74 7 3 2 Science observing TSF 77 7 3...

Страница 5: ...s Acronyms and Abbreviations Throughout this document we will use the terms CRIRES and oCRIRES to refer to CRIRES after and before the upgrade respectively However it should be noted that the instrument name has not changed This document employs several abbreviations and acronyms to refer concisely to an item after it has been introduced The following list is aimed to help the reader in recalling ...

Страница 6: ...d Visitor mode Observation Blocks OBs should be prepared with the latest version of the Phase 2 web based preparation tool p2 available at https www eso org sci observing phase2 p2intro html Information for the preparation of the Service mode observations with CRIRES are available at http www eso org sci observing phase2 SMGuidelines CRIRES html Visiting astronomers do not need to submit OBs in ad...

Страница 7: ... quality control can be found at http www eso org observing dfo quality 1 4 Contact Information In case of specific questions related to proposal preparation Service Mode observations and the use of the pipeline please contact the ESO User Support Department usd help eso org For Visitor Mode observations please contact the Paranal Science Operations Team For general information use paranal eso org...

Страница 8: ...instrument parameters is given below Spectral resolution 50 000 and 100 0001 Wavelength coverage 0 95 5 3 μm YJHKLM bands RV precision 3 m s by using gas cells Slit length 10 arcseconds Slit width 0 2 and 0 4 arcseconds Slit length 10 arcseconds Polarimetry linear circular YJHK bands Adaptive optics 60 actuator curvature sensing MACAO Cross disperser 6 gratings YJHKLM 1 See 4 4 7 for more details ...

Страница 9: ...ving efficiency for many scientific programmes requiring a broad spectral coverage The CRIRES upgrade project CRIRES has transformed this VLT instrument into a cross dispersed spectrograph with the goal to increase the simultaneously covered wavelength range by a factor of ten A new and larger detector focal plane array of three Hawaii 2RG detectors with 5 3μm cut off wavelength replaced the exist...

Страница 10: ...g most of their energy in the IR 1 0 2 5 μm a high resolution IR spectrograph is therefore ideal for searching for low mass planets around these objects A new gas absorption cell to provide a stable wavelength reference as well as the increase in wavelength coverage by about a factor of ten should result in an attainable RV precision for the upgraded CRIRES of 3 m s 1 This would enable the detecti...

Страница 11: ...ting of a spectral line is proportional to λ2 so there is a huge leverage in going to the IR 2 For cool objects most of the flux is in the IR so there is also a gain due to the increased signal to noise ratio 3 In order to disentangle Zeeman broadening from other broadening effects one must compare the broadening of Zeeman sensitive lines to magnetically insensitive lines The large wavelength cove...

Страница 12: ...O system can be found in sec 3 2 1 of this manual CRIRES can be used without adaptive optics in which case the AO module just acts as relay optics and the spatial resolution is given by the natural seeing Under normal conditions this leads to higher slit losses than when AO is used 3 1 The Cold Part Opto mechanics After the dichroic window the infrared light passes through a new entrance slit unit...

Страница 13: ...RES fore optics assembly Figure 4 shows that the beam from the f 15 focus at the new entrance slit A is collimated by a parabolic mirror B and arrives at the cross disperser wheel E via two flat mirrors and a long pass filter wheel C to block the 2nd and higher orders of the cross disperser gratings The jitter mirror D has two piezo actuators that allow the echellogram to be translated at sub pixe...

Страница 14: ...ra to image the spectrum on the new three Hawaii 2RG detectors effectively forming an 6144x2048 pixels array More details on the optical and opto mechanical designs can be found in Lizon et al 2014 and Oliva et al 2014 respectively 3 1 3 The new detectors Another major part of the upgrade project was to increase the coverage of the focal plane by introducing a set of new detectors To accommodate t...

Страница 15: ...tor mount left All detector systems including the slit viewer camera is upgraded to the current ESO standard New General detector Controller NGC This detector upgrade does not only significantly increase the coverage of the focal plane but the increased spatial homogeneity of the pixel response combined with lower readout noise dark current and higher QE will result in improved data quality All de...

Страница 16: ...eywords written to their headers values below are examples HIERARCH ESO OCS MTRLGY DX 0 002 pixels Final mean x residual relative to fiducial HIERARCH ESO OCS MTRLGY DY 0 039 pixels Final mean y residual relative to fiducial HIERARCH ESO OCS MTRLGY ECHCORR 54 Enc Difference between the nominal echelle encoder value and the resulting value after metrology HIERARCH ESO OCS MTRLGY ECHNMOV 1 Number of...

Страница 17: ...ellogramme alignment was somewhat higher 0 2pix over 30mins following metrology alignment than it was without metrology 0 05pix over 30mins consistent with PAE measurements and specifications This effect is still being investigated and several mitigation strategies are under consideration but users should keep in mind that during P108 spectral resolution and alignment of data obtained within 30min...

Страница 18: ...ve optics and atmospheric turbulence and essentially is taken from the NACO user manual For further reading see for example Adaptive optics in astronomy Rodier 1999 Cambridge University Press or Introduction to adaptive optics Tyson 2000 Bellingham SPIE 3 2 1 1 Atmospheric Turbulence The VLT theoretical diffraction limit is 1 22 l D 0 07 arcsec at a wavelength of 2 2 μm However the resolution is s...

Страница 19: ...onger than the turbulence coherence time The residual error from the WF compensation WF error directly determines the quality of the formed image One of the main parameters characterizing this image quality is the Strehl ratio SR which corresponds to the amount of light contained in the diffraction limited core relative to the total flux An AO system is a servo loop system working in closed loop T...

Страница 20: ... good correction in the K band typically corresponds to a SR larger than 30 At shorter wavelengths particularly in the J band or in the case of poor conditions or a faint distant reference source the correction is only partial the SR may only be a few percent 3 2 2 MACAO Hardware Description The MACAO system for CRIRES is based on a 60 actuator deformable mirror inserted in a so called relay optic...

Страница 21: ...atmospheric aberrations up to an optical seeing of 1 In order to relax the use of the outer electrodes of the mirror the tip tilt error is slowly offloaded to a tip tilt mount designed and built by LESIA which provides a 240 mechanical stroke i e 3 6 on the sky with a 100 Hz 3dB internal closed loop bandwidth The assembly of the DM and tip tilt mount is shown in Figure 12 Figure 12 Assembly of the...

Страница 22: ... position of the field selector the gimbal mount is moved so that the light is reflected to the same focus A diaphragm in front of the membrane enables the field to be adjusted to the observing conditions seeing and guiding reference size The assembly of the gimbal mount is shown in Figure 12 The wavefront sensor box consists of 4 mirrors which provide parallel beam to image the pupil on the lensl...

Страница 23: ...the curvature of this mirror Increasing the curvature however requires increasing the field of view of the wavefront sensor optics as well This and some other non linear effects can degrade the estimate of the curvature For the same reason extended sources will affect the quality of curvature measurement and lead to a different optimal gain In some extreme cases the system can be unable to close t...

Страница 24: ...r see Figure 16 i The new polarimetry unit ii a gas cell either for wavelength calibrations when used with the halogen lamp which creates an absorption spectrum or for accurate radial velocity measurements similar to the way for the iodine cell technique ii a pinhole used for calibration purposes iii an AO fiber for MACAO calibrations iv an Uranium Neon UNe Lamp for wavelength calibration This car...

Страница 25: ... novel IR absorption gas cells with multi species gas fillings NH3 13 CH4 C2H2 These gases will provide a set of densely distributed absorption lines imprinted on the stellar spectra in the H and K bands see Figure 17 In addition the existing Thorium Argon hollow cathode lamp is replaced with similar Uranium Neon lamp that produce a richer wavelength calibration spectrum Figure 17 Spectral coverag...

Страница 26: ...k separation free spectral range FSR and the line strength sharpness contrast The FSR and contrast can thus be tuned and optimized to match the spectrograph s resolving power sampling and wavelength range Figure 18 Top 3D Model of the FPI system in the vacuum chamber cut view The vessel layout and gauges are also shown Bottom Simplified working proto type FPI unit The major advantages are comb lik...

Страница 27: ...e Not a part of routine flat field calibration during P108 Krypton Ne pen ray lamps Metrology Integrating Sphere Sparse spectral features which however provide an easily reproducible uniform illumination of the entrance slit for metrology Can be attenuated with the baffle He Ne Laser Alignment health checks on resolution Feeds Integrating Sphere Dual wavelength 1 1526μm and 3 3922μm Coupled to an ...

Страница 28: ...etric unit is very compact and is installed on CRIRES calibration slide see Figure 16 The polarization unit includes two circular polarisation beam splitters for YJ and HK bands and two beam splitter for YJ and HK bands combined with an achromatic quarter wave retarder plate QWP for the linear polarization Two types of PGs are used for the CRIRES SPU HK PGs with a wavelength limits band from 1480 ...

Страница 29: ...CRIRES User Manual Doc Number ESO 323064 Doc Version 2 Released on Page 29 of 82 Document Classification Public ...

Страница 30: ...dispersion is reached without the metrology system and 0 3px when the metrology is enabled In L and M bands the absolute wavelength repeatability is of the order of 10 px 4 2 AO performance The performance achieved by the MACAO system of CRIRES has been evaluated by laboratory simulations comparing two cases i in close loop with guide star of various magnitudes and ii in open loop i e without AO c...

Страница 31: ... wavelength of 1559 245 nm taken in atmospheric condition corresponding to Turbulence category 50 in open and closed loop In both cases the exposure times were the same however in closed loop a flux level being about 1 8 times higher was attained than in the open loop observations Figure 21 Improved throughput thanks to the use of AO H band flux of the star Pi 02 Ori measured along the 0 4 slit in...

Страница 32: ...ately forwards its signal to the RTC The flux on an APD is limited to 1 million counts in order not to damage the devices The optimal brightness of the AO star is R 11 mag Brighter stars up to a bright magnitude limit of R 0 2 mag can be dimmed using neutral density filters Depending on the B R colour some stars with slightly brighter R magnitude can be used Good correction is still obtained with ...

Страница 33: ...cts or observations in the L or M bands high sky background require short DITs to avoid saturation in particular heavily saturated spectra lead to detector remanence that affects subsequent observations Because the only offered detector read out mode is the Sample Up The Ramp DET1 READ CURNAM New_RR_UpTheRamp users must supply only the required DIT the read mode software then determines the minimu...

Страница 34: ...cs is provided in Table 2 Table 2 Summary of science detector parameters Parameter DETECTOR 1 DETECTOR 2 DETECTOR 3 Serial Number SN17308 SN17306 SN17310 Dark current e s 0 03 0 03 0 03 Thermal background e s 0 05 0 05 0 05 Gain e ADU 2 28 2 19 2 00 Quantum Efficiency 2000nm 93 98 95 RON e RMS DIT 40s 11 12 12 DIT 40s 6 6 6 Saturation ADU px 37000 37000 37000 Non linearity ADU px 1 6000 6000 6000 ...

Страница 35: ... view Target centring and NGS acquisition are performed in the NIR via the Slit Viewer camera SV Because CRIRES observations require the use of a guide star SVGS to ensure that the target is properly kept centred along the slit during the science exposures the SVGS is also acquired through the SV camera With a pixel scale of 37 3 mas the SV covers a maximum unvignetted sky projected field of view ...

Страница 36: ...an area of 0 4 x10 located 3 6 Eastwards with respect to the FoV centre see vertical dark stripe When the 0 4 slit is used there is no vignetting from the 0 2 slit as its footprint falls at the border of the FoV 4 4 2 Slit viewer limiting magnitude The SV is equipped with 5 NIR filters J H K and 2 neutral density H filters The SV is sufficiently sensitive that any emitting point source for which o...

Страница 37: ...ta Reduction Software DRS No free settings are offered Figure 26 A 1D extraction of the flat field image indicating the spectral coverage achieved for a single echelle setting obtained in a single exposure K band echelle angle 65 5 The three different detectors are colour coded differently To reduce the total number of fixed settings offered by CRIRES the number of settings per photometric band we...

Страница 38: ...ddle of slit Spectral coverage for full slit Band Starting λ nm Ending λ nm Starting λ nm Ending λ nm Starting λ nm Ending λ nm Y 955 1120 948 1120 948 1120 J 1100 1400 1116 1356 1116 1331 H 1500 1800 1423 1854 1461 1796 K 2000 2400 1908 2527 1946 2472 L 3200 3700 2810 4150 2840 4100 M 4600 5000 3340 5800 3360 5600 1356nm 85 of slit 2501nm 75 of slit The detector cut off is 5300nm 4 4 4 Wavelength...

Страница 39: ...gnificantly less than the expected R 100 000 There is some expected variation with echelle grating angle and R 100 000 has been measured in some configurations Nevertheless for P108 users should not expect R 80 000 Full characterisation of the issue is ongoing and several options exist for recovering the expected spectral resolution 4 4 8 Radial velocity precision The short gas cell SGC provides a...

Страница 40: ... standard Pi2Ori by using the AO modes and the 0 4 slit width The total throughput was derived by scaling the observed spectrum expressed in e s px and corrected for silt loss by the theoretical Figure 28 shows the overall efficiency measured on the observed spectrophotometric standard in four different settings i e Y1029 J1228 H1559 and K2148 The throughput over the whole spectral range can be do...

Страница 41: ... Doc Version 2 Released on Page 41 of 82 Document Classification Public That being said based on these preliminary results obtained during the commissioning run in January 2021 the throughput is found to be about 10 15 higher than the oCRIRES ...

Страница 42: ... Phase I General information and User Constraints As for all Paranal instruments there are two Phases I and II in the application for time with CRIRES Phase I starts with the Call for Proposals issued by ESO twice per year At each call2 users must create a proposal with p1 the web based tool for proposal preparation available at www eso org p1 Using this tool user is requested to provide both scie...

Страница 43: ...aspects of near IR observations that influence the choice of the observing constraints set and the observing strategy hence consequently the total telescope requested time 5 2 1 Turbulence Category As of Period 105 the Phase I seeing constraint i e seeing at the zenith in V band has been replaced by the Turbulence Category TC For CRIRES NoAO observations the TCs are defined using the percentiles o...

Страница 44: ...5 2 2 Atmospheric transmission and Precipitable Water Vapour The transmission of the Earth s atmosphere in the J H K L and M bands is shown in Figure 29 Figure 29 Atmospheric transmission from 900 5500nm computed by PCLnWin HITRAN for Paranal atmosphere PWV 2 5mm at zenith and smoothed to a resolution of λ Λ 104 ...

Страница 45: ...e the identification of sky regions affected by Precipitable Water Vapour PWV lines Figure 30 shows the atmospheric transmission spectrum only including PWV absorption lines Figure 30 PWV sensitive atmospheric transmission from 900 5500nm computed with RFM HITRAN for Paranal atmosphere PWV 2 5 mm at zenith at resolution of λ Λ 100000 ...

Страница 46: ...n varies non linearly with zenith distance and PWV see Figure 32 The transmission spectrum of the sky for a particular setting is an optional output provided by the ETC which allows one to select spectra based on different amounts of PWV i e Figure 31 The available values range from a minimum of 0 05 mm to a maximum of 30 mm The median value of the PWV on Paranal is 2 5 mm Note that the PWV is a m...

Страница 47: ...sensing is fainter than R 14 mag In this case reducing the FLI constraint to 0 7 and increasing the distance to the Moon to approximately 50 degrees is recommended 5 2 4 Sky Transparency Thin clouds THN usually do not hamper CRIRES observations for bright objects Clear CLR conditions are justified for observations requiring stable AO corrections for example to study the close environment of the ta...

Страница 48: ...e nods between the two positions A and B The number of nodding cycles i e number N of AB pair spectra and the nodding throw i e separation between the A and B positions are free observing parameters However in spectro polarimetry mode the nodding throw is fixed at 2 5 The number of defined AB pair affects the total amount of overheads therefore already at Phase 1 we strongly encourage the user to ...

Страница 49: ... water vapour content of the Earth s atmosphere https www eso org sci software pipelines skytools molecfit This tool is based on the work presented in Seifahrt et al 2010 A A 524 11 this work discusses the performance and limitations of the technique to synthesize telluric absorption and emission line spectra 5 2 6 3 Telluric correction via telluric standard stars In case that users wish to observ...

Страница 50: ...Noise Ratio SNR given the Target properties the Instrument setup and the constrains set i e Sky Seeing and IQ see Figure 33 A detailed description of all ETC input and output parameters is given on the web page however below we provide some general guidelines and advise on the main ETC features Figure 33 Screenshot of the CRIRES ETC Exp Time tab User requests the desired SNR by using a given DIT a...

Страница 51: ...d TC or image quality IQ at a given reference wavelength The ETC provides automatic conversion between the TC i e phase 1 constraint and IQ i e phase 2 constraint The seeing is given exclusively in term of TC when the AO mode is selected Hence in this case TC is the relevant constraint for phase 1 and 2 AO observations are restricted to TC 10 20 30 50 70 and 85 SNR calculations for larger values i...

Страница 52: ... lead to very different SNR for a given total integration time or alternatively very different integration time for a requested SNR From the ETC page users can access to a python script that allow to download the output of the requested plots in ascii file 5 4 Instrument overheads In Phase 1 users are requested to provide the total execution time which is given by the total exposure time i e open ...

Страница 53: ...53 of 82 Document Classification Public CRIRES Nodding cycle 24 CRIRES Change of wavelength setting 80 CRIRES Metrology in YJ 110 CRIRES Metrology in HK 180 CRIRES Attached wavelength calibration 150 CRIRES Attached lamp flat 120 CRIRES Change of derotator position angle 60 ...

Страница 54: ... html CRIRES news http www eso org sci facilities paranal instruments crires news html Service Mode SM http www eso org sci observing phase2 SMGuidelines html Visitor Mode VM http www eso org sci observing phase2 VMGuidelines html and http www eso org sci facilities paranal instruments crires visitor html Finally the preparation of CRIRES OBs spectroscopic modes can be easily performed with the he...

Страница 55: ...r the Target Visibility tab within p2 or the tools available at http www eso org sci observing tools calendar airmass html Visitors should bear in mind that in case of strong wind and subsequent telescope pointing restrictions is might not be able to observe their main targets For this reason it is strongly recommended to prepare backup targets with declinations smaller and larger than 24 6 Such b...

Страница 56: ...e target position a guide star in the FoV of the telescope is selected for telescope guiding and to correct the M1 mirror shape active optics not to be confused with adaptive optics AO 2 In NGS mode the telescope moves then to the NGS specified by the user Once the NGS is centred on the MACAO field selector the AO loop is closed 3 The telescope moves to the SVGS which is then acquired and centred ...

Страница 57: ...ential velocities for moving targets are to be specified directly in the ephemerids PAF file 6 3 5 In what follow we describe all parameters present in the acquisition templates that the user is requested to define as well as their relevance in terms of selected instrument mode VLT GuideStar GS details Telescope guide star selection TSF TEL AG GUIDESTAR if set to CATALOGUE the Telescope Control Sy...

Страница 58: ...PHA TEL TARG OFFSETDELTA correspond to the offsets in arcsec necessary to move from the target to the SVGS If α SVGS and δ SVGS are the coordinates of the SVGS the sign convention is as follows TEL TARG ALPHA TEL TARG OFFSETALPHA α SVGS TEL TARG DELTA TEL TARG OFFSETDELTA δ SVGS In other words TEL TARG OFFSETALPHA and TEL TARG OFFSETDELTA are positive if the SVGS is located to the East and North o...

Страница 59: ...F SEQ NGS MAG refers to the magnitude of the NGS in the R passband See 4 2 1 3 for the allowed range AO guide stars FWHM arcsec TSF SEQ NGS FWHM gives the FWHM of the NGS in arcsec used to optimize the AO system diaphragm This diaphragm is set as a function of the seeing and as such it optimizes the amount of light received from the object with respect to the amount of background light from the sk...

Страница 60: ... details Entrance slit width TSF INS SLIT1 NAME w_0 2 i e 0 2 slit width for a spectral resolution of R λ Δλ 100 000 or w_0 4 i e 0 4 slit width for R 50 000 Reference wavelength TSF INS WLEN CWLEN allows the user to select from a pull down menu the wavelength value that uniquely identify the wavelength setting i e cross disperser order sorting filters echelle grating The settings and correspondin...

Страница 61: ...ted for point source like targets is the nodding along the slit where the target is always kept along the slit i e no off slit exposures are possible and the sky signal is removed from the object spectrum by subtracting two exposures taken at different slit positions On the other hand when the target is an extended object nodding along the slit is no longer a viable strategy because removing the s...

Страница 62: ...r because of the high risk of not meeting atmospheric quality requirements In visitor mode other DITs can be chosen but at the expense of additional calibrations NDIT TSF DET1 NDIT determines the number of individual integrations averaged into one exposure therefore DET1 NDIT x DET1 DIT sets the total integration time of one exposure Normally FITS files are only written for the average of NDIT sub...

Страница 63: ...posang TSF SEQ JITTER RESET Only relevant for spectro astrometric observations and when SEQ JITTER WIDTH Jitter width is not zero If this parameter is set to yes i e SEQ JITTER RESET T the list of jitter positions calculated by the observation software is repeated identically in detector coordinates for each value of the slit position angle Examples for Nodding 1 If SEQ NABCYCLES 1 the telescope f...

Страница 64: ...to SKY a positive value in SEQ OFFSET1 LIST means that the new pointing of the telescope is to the East relative to the previous location target moves West on the SV similarly a positive value in SEQ OFFSET2 LIST means that the new pointing of the telescope is to the North relative to its previous location target moves South on the slit viewer During the first exposure the telescope points to the ...

Страница 65: ...ET1 NDIT OBJECT x DET1 DIT Similarly the total integration time of one exposure in SKY location is DET1 NDIT SKY _DET1 DIT Note that SEQ NEXPO exposures can be obtained at each location In the case of NGS observations OBJECT and SKY correspond to MACAO CLOSE and OPEN loop respectively Figure 34 Illustration showing the apparent locations of the target as seen from the SV detector for the given par...

Страница 66: ...on angle of 0 in SKY mode the reconstructed SV image shows North up and East left 6 3 3 Night time calibrations Darks flat fields and wavelength calibrations are taken during daytime as part of the calibrations plan see 0 for more details A Halogen lamp is used for flat fields while UNe lamp or the N2O or SGC gas cell in front of the halogen lamp are used for wavelength calibration However dependi...

Страница 67: ...trophotometric standards supported by the pipeline see Table 10 then the pipeline outputs also the sensitivity and total throughput i e spectrograph telescope Earth atmosphere Table 10 Spectrophotometric standards supported by the pipeline Name RA DEC Rmag B R HR9087 00 01 49 45 03 01 39 1 5 1 0 12 HR718 02 28 9 54 08 27 36 2 4 3 0 05 GD50 03 48 50 2 00 58 31 2 14 21 0 42 HZ2 04 12 43 55 11 51 48 ...

Страница 68: ...efines the Wavelength calibration source TSF INS LAMP Possible choices are UNE for the Uranium Neon lamp 2500 nm FPET for the Fabry Perot Etalon system 2500 nm HALOGEN to be combined with any of the gas cells INS OPT1 NAME GAS_SGC or GAS_N2O Note that the FPET should be executed together with the UNE lamp to establish the zeropoint of the FPET 6 3 3 4 Darks Darks are obtained during daytime calibr...

Страница 69: ...time difference from the evening twilight end and sun elevation varies during the year for Paranal due to its low latitude this difference is small Therefore the constraint is given in minutes as a difference in time with respect to the end of astronomical twilight i e the time when the solar elevation is 18 degrees The default TW value 15 minutes A negative number means that it is allowed to star...

Страница 70: ...should cover the assigned time night The ephemeris files are ASCII files compatible with the VLT parameter file PAF format and can be prepared by using the online tool available at http www eso org sci observing phase2 SMSpecial MovingTargets html 6 3 6 Finding Charts For SM observations users are requested to provide finding charts for any given science OB Finding chart must be compliant with ESO...

Страница 71: ...CRIRES User Manual Doc Number ESO 323064 Doc Version 2 Released on Page 71 of 82 Document Classification Public ...

Страница 72: ...setup as the science etc wavelength calibrations and flat field exposures will be taken through the 0 2 or 0 4 slit The daily calibrations are taken by employing the metrology system Table 11 Standard calibrations Calibration Number Matching parameters Validity Darks 3 DIT 1 day Flats 3 wavelength slit width 1 day Wavelength FP etalon 1 wavelength slit width 1 day Wavelength UNe lamp 1 wavelength ...

Страница 73: ...LUMN 4 Setting maximum wavelength in nm stored in the parameter FITS header INS EWLEN MAX COLUMN 5 Grating orders range covered by the setting COLUMN 6 Minimum grating order providing full slit spectral coverage COLUMN 7 Maximum grating order providing full slit spectral coverage Table 13 Wavelength coverage of CRIRES settings Name Ref Wave LambdaMIN LambdaMAX Grating Order range MIN complete Grat...

Страница 74: ...1 16 M4504 4504 089 3628 157 5900 475 10 16 11 16 M4461 4461 195 3591 705 5847 312 10 16 11 16 M4416 4415 885 3553 308 5791 199 10 16 11 16 M4368 4368 182 3512 986 5731 778 10 16 11 16 M4318 4318 114 3470 761 5669 235 10 16 11 16 M4266 4265 706 3426 660 5603 639 10 16 11 15 M4211 4210 988 3379 981 5535 012 10 16 10 15 M4187 4186 838 3360 014 5504 897 10 16 10 15 7 3 Template Signature Files 7 3 1 ...

Страница 75: ...CATALOGUE Telescope guide star selection TEL GS1 ALPHA 0 0 RA of telescope guide star TEL GS1 DELTA 0 0 DEC of telescope guide star TEL TARG OFFSETALPHA 15 15 0 0 RA offset between target and SV guide star TEL TARG OFFSETDELTA 20 20 0 0 DEC offset between target and SV guide star INS OPTI1 NAME FREE GAS_N20 GAS_SGC FREE Optional optical element INS DROT MODE SKY ELEV NODEFAULT Derotator Mode INS D...

Страница 76: ... CATALOGUE Telescope guide star selection TEL GS1 ALPHA 0 0 RA of telescope guide star TEL GS1 DELTA 0 0 DEC of telescope guide star TEL TARG OFFSETALPHA 15 15 0 0 RA offset between target and SV guide star TEL TARG OFFSETDELTA 20 20 0 0 DEC offset between target and SV guidestar INS OPTI1 NAME FREE GAS_N20 GAS_SGC POL FREE Optional optical element INS DROT MODE SKY ELEV NODEFAULT Derotator Mode I...

Страница 77: ...lit i e recommended for all point source like targets The following two science observing templates are not available in observing period 108 CRIRES_spec_obs_GenericOffset AO and NoAO spectroscopic observations performed by moving the target along and off slit according to user defined offsets pattern i e recommended for extended objects CRIRES_spec_obs_SpectroAstrometry AO and NoAO spectroscopic ...

Страница 78: ...pec_obs_GenericOffset To be specified Parameter Range default Label DET1 DIT 0 900 NODEFAULT DIT DET1 NDIT OBJECT 1 100 1 NDIT for the OBJECT positions DET1 NDIT SKY 1 100 1 NDIT for the SKY positions SEQ NEXPO 1 100 1 Number of exposures on each position SEQ NOFF 1 100 1 Number of offset positions SEQ OBSTYPE LIST O S NODEFAULT List of observation types O or S SEQ OFFSET COORDS SKY DETECTOR SKY O...

Страница 79: ...cycles SEQ NODTHROW 0 8 8 Nod throw along the slit SEQ NEXPO 1 100 10 Number of exposures per nodding position SEQ JITTER WIDTH 0 8 0 Jitter width SEQ JITTER RESET T F T Reset jitter for each DROT posang INS DROT POSANG LIST 0 0 360 0 List of position angles in degrees cumulative values INS OPTI1 NAME FREE GAS_N20 GAS_SGC FREE Gas cell INS SLIT1 NAME w_0 2 w_0 4 0 2 Entrance silt width INS WLEN CW...

Страница 80: ...ODEFAULT DIT DET1 NDIT 1 1000 1 NDIT SEQ NABCYCLES 0 100 1 Number of nodding cycles SEQ NODTHROW 0 8 8 Nod throw along the slit SEQ NEXPO 1 100 10 Number of exposures per nodding position SEQ JITTER WIDTH 0 8 0 Jitter width INS SLIT1 NAME w_0 2 w_0 4 0 2 Entrance silt width INS OPTI1 NAME FREE GAS_SGC GAS_N20 Gas cell INS WLEN CWLEN See Table 13 Standard wavelength setting INS METROLOGY T F F Impr...

Страница 81: ...age in the light path HIERARCH ESO SEQ NODPOS Nodding position A or B HIERARCH ESO SEQ NODTHROW Nodding throw along the slit in arcsec HIERARCH ESO AOS RTC LOOP STATE AO loop state open or closed HIERARCH ESO OCS MTRLGY ST T if metrology converged Keyword only present if metrology was used 7 4 3 Pipeline CRIRES comes with a new Data Reduction System DRS package that is incompatible with data from ...

Страница 82: ...aster calibrations and science data as input and perform all necessary reductions steps until the final products cr2res_util_ are recipes with smaller scope typically executing a single reduction step each These are both useful for testing and for manual step by step reductions All offered observing modes are supported and data products are deemed to be science ready The pipeline and corresponding...

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