Number of argon wavelength calibration lamps to be obtained during
twilight (when standard cals are taken) in addition to any
STDCALS or EXTRACALS Ar comparison arcs.
Exposure time will be the default for the current setup; otherwise use
EXTRACALS.
For tracks that should only be done at one specific azimuth, specify E or W.
If no azimuth restriction is needed, omit this keyword or leave this field blank.
This parameter is used primarily form MOS, moving targets, and synoptic targets.
For MOS targets this parameter is required because the Tracker rho ring is limited to 180 degrees of rotation
and thus East and West tracks will be flipped, requiring different configuration files. For tracks far north or far south the amount of rho
angle rotation allows for similar East and West Tracks.
Keep it as brief as possible, starting with anything vital to know about at the
time of execution, e.g. any request ("Take adjacent ThAr") or ID clarification
("Fainter star of close pair") or intention that might be misread from a finding
chart ("Transect BOTH nuclei with the slit").
For blind offset setups, give the name of the .xy setup file.
For MOS setups, give the name of the .cfg setup file.
For MOS setups, also specify whether this is the West or East track.
Users tend to confuse the intentions of the COMMENT and the NOTES
keywords (see below). COMMENT is for the most concise, vital, real-time
instructions necessary for the visit of this target; NOTES are intended to apply to all targets but should still be concise.
Format Examples: COMMENT "Take
adjacent ThAr" COMMENT template_exposure
Number of sub-exposures in which to split the total exposure time for a visit.
For long (>20 minutes) LRS EXP total integration times, use
CRSPLIT to break up the time not only for cosmic ray censoring,
but also for quality checks upon target centering and focus.
A CRSPLIT of 1 means no sub-exposures, i.e. one single exposure.
For example, an exposure time of 1800 sec with a CRSPLIT of 2 means two 900 sec exposures.
Use either CRSPLIT or NUMEXP, but do not mix the two in a single TSL file.
If the goal is to fill the track maximally with exposures, please also
inform the RA as to the minimum acceptable length for any "runt" exposure
split to be fit in if the end-of-track must curtail the final
split. Without explicit guidelines in this situation, a final "runt" split will
be undertaken only if it attains at least 50% of nominal length.
If covering an entire track with split exposures, be aware of the
considerable readout overhead entailed by CRSPLIT >> 1. A good
tactic is then to make the exposures as long as possible, but this brings in
the changing HET effective pupil. In the light of this please inform the RA
if instead of equal length exposure splits, you would prefer an automated
alternative of equal depth exposure splits (as modulated by the effective
pupil).
Number of dark frames to be obtained during the night
in addition to any EXTRACALS dark frames.
Darks are no longer included in the standard set of calibrations
due to the very large required overhead and the request will have to be
supported by a scientific justification.
The binning will match that of the science target.
This value sets the echelle rotation angle for changing the position of the orders on the CCD, primarily to move spectral
features of interest off CCD defects.
central: Default value. It is intended to center the orders on the CCD, and yield the (theoretical) wavelengths
given below in the Cross Disperser table (see keyword XD). In practice, the blaze peaks are slightly to the red side of the CCD.
blue: Causes the wavelength approximately at the blue end of the orders to be moved to the center of the CCD. The blaze
peak of the order (peak efficiency) moves near the red edge of the CCD.
red: Causes the wavelength approximately at the red end of the orders to be moved to the center of the CCD.
The blaze peak of the order (peak efficiency) moves near the blue edge of the CCD.
If CRSPLIT is used, EXP is the total exposure
time in seconds for the Action, and each frame exposure is the CRSPLIT-fold divided fractional part. Normally the exposure
depth contrast due to the slowly changing effective pupil is very minor
(but if the visit covers the entire track end-to-end, see the
CRSPLIT keyword description for more on this).
If NUMEXP is used instead, this is the exposure time per frame.
If neither is specified, this is the exposure time for the (single) frame.
Used to specify the number count and exposure time for a list of calibration frames to be obtained during twilight (when standard cals are taken) in addition to
any STDCALS calibrations or add-on calibrations such
as e.g. THAR. It is one tool for adding calibrations of an unusual integration
length or unusual nature given the science target setup (the other being to
form individual "standalone" targets out of the said calibrations).
The general format of an extra calibration is:
<number of exposures>x<calibration type>[@<exposure>s]
Exposure times are in seconds.
If the exposure time is omitted, a default for the current setup is assumed.
Multiple calibration types must be separated by commas and placed in double quotes.
The MRS fiber arm has two axes of motion, so it is a very simple action to switch between the sky fiber and the object
fiber. The desired fiber can be specified with this keyword.
The default is to always use the target fiber, but nodding between the two is possible.
0: For all Direct Feed exposures there is a hardwired filter. It is a Schott type OG455 for the "R" fibers and a
WG305 for the "B" fibers. One should be aware that there will be XD second order overlap beyond 9000 Å for the "R"
fibers. There is the potential for XD second order overlap beyond ~7500 Å for the "B" fibers depending on the blue spectral
energy distribution of the target.
There will be up to six filter options to be defined in future LS or MOS modes:
Give the needed quality level of flux standard, according to the HET flux standard quality listing. E.g. 3 for level three or better
flux standards, or Y for any flux standard.
If no flux standard is required, enter N. If a particular
selection of flux standards is preferred to all the others, not
consistent with this basic "quality level" selection scheme, please
inform the RAs.
Assign a name to related objects collected into a GROUP.
Group names must be unique within a given program.
Groups should fulfill the requirement of needing to be executionally linked,
in the sense that the "ungrouped" execution of their separate members would be
devalued. An example would be the spectrum of a galaxy halo that would need an
immediately following spectrum of the nearby night sky, constituting a SEQ group.
Frankly, think of grouping as an available tool, with the default being NOT to
use it.
Specify the relationship between the targets in a GROUP.
___acquisition on ONE night___
SEQ - Execute all actions in the GROUP on the same night in the specified sequence, with no other
observations permitted in between even if the actions are in separate tracks.
AND - Execute all tracks in the GROUP on the same night, with other interleaved observations permitted.
___acquisition on MULTIPLE nights___
ORD - Execute all tracks in the specified order across one or more nights, with other interleaved observations permitted. The ordering
is what distinguishes from unrelated targets.
POOL - Execute NUMTODO number of tracks out of the total tracks listed in the GROUP. The subsampling is what
distinguishes from unrelated targets.
Number of mercury wavelength calibration lamps to be obtained
during twilight (when standard cals are taken) in addition to any STDCALS or EXTRACALS Hg
comparison arcs.
Exposure time will be the default for the current setup;
use EXTRACALS.
Number of neon wavelength calibration lamps to be obtained
during twilight (when standard cals are taken) in addition to any STDCALS or EXTRACALS Ne
comparison arcs.
Exposure time will be the default for the current setup;
otherwise use EXTRACALS.
Notes that apply to all tracks, used in the COMMON section of the TSL file.
Users tend to confuse the intentions of the NOTES and the COMMENT
keywords (see above). COMMENT is for the most concise, vital, real-time
instructions necessary for the visit of this target; NOTES is for all targets within the program but should still be concise.
Avoid spaces, so for "NGC 3379" use NGC3379 or NGC_3379.
Names will be truncated downstream at 18 characters, so it is appreciated if the PI limits to 18 characters e.g. by chopping the least significant RA and Dec digits
(SDSS users!). Bear in mind that the PI's preferred style of truncation to a maximum
of 18 characters, might not match what the RAs have ended up having to do to the overly long name entry; thus curtail your object name lengths pro-actively.
For MOS setups, please append "W" or "E" for West or East track.
Unique object names lead to fewer problems down the road.
The calculated nominal PA corresponds to the LRS science chip y-axis and
the LRS science slits lie at a small net PA shift of +0.5 degrees to that.
For lining up two separated targets on a narrow slit the observer generally
compensates by adding an extra rho offset of +0.5 degrees [equivalent
to setting to delta PA -0.5 degrees from nominal]. Then the slit rather
than the y-axis precisely matches the double target PA.
Allows the PI to provide a URL for a finder chart for the target. Initially charts will be assumed to reside on the PI's website, and will be
retrieved by the RA. Precede with https:, http:, or ftp:
Give the needed quality level of RV standard, according to the HET
radial velocity standard quality listing. E.g. 3 for level three or better
RV standards, or Y for any RV standard. Note that "5" is for M giants and quality "4" are probably only good for LRS low resolution standards.
This is an integer number that specifies the number of object-sky switches to be done.
Each exposure will be the total exposure time in the Phase II exposure line divided by this number.
1: One exposure of specified length with object in default fiber.
2: If using 1.5R or 1.5B, do second exposure of specified length with object moved to sky fiber
in first exposure. If using 2R or 2B, object moved off fiber for second sky-only exposure.
Available when FIBER=3as, SKYFIBERS=0sky, and RES is one of 30k, 60k, or 120k. The increase in throughput versus
the 3as fiber is 41%. Orders overlap depending upon XD as follows:
Submit your targets as either ready (using "" not " ")
or deferred (represented by D) until your later activation.
The synoptic and phase-blocking software will automatically sort out
if and when the ready target must be blocked (represented by H) or
or revert to unblocked (once again ""), with no PI input needed.
When you wish that a particular target be no longer used
(whether its tally of visits is fulfilled or not), ask for it to
be marked as deferred (represented by D).
When you wish that a deferred target be activated or re-activated
to ready, the synoptic or phase-blocking software will take care of sorting
out whether the status becomes ready and unblocked (represented by "")
or ready but blocked (represented by H).
A boolean string Y or N to specify whether the standard calibration set should be taken during the night.
If Y, note that now any special calibrations specified elsewhere are taken in addition to the standard calibration set. This is
a change in meaning from the previous usage of the standard cals question where any calibration requirements other than
the standard set required an answer of no.
The STDCALS formalism provides the bulk of HET science data
calibrations, but additional methods are provided by add-on cals such as e.g.
THAR, by the EXTRACALS formalism, and by if necessary forming
cals into individual "standalone" targets on their own (typically grouped
with associated science targets). This last method is however subject to
TAC time charging to the extent that it consumes science time.
For synoptic targets with visits required before, on, or after specific
UT dates.
Format for dates should be sYYYYMMDD in UT dates, where s is either an
= meaning precisely on this date, or a >
meaning on or after this date, or a <
meaning on or before this date.
Multiple specific dates can be separated by a comma with no space e.g. =20070412,=20070415 or with a dash, e.g. =20070412-20070415. If your targets
have different exposure times or azimuth restrictions on these dates then you will have to make them separate entries.
Date ranges may be given by using two different formats: >20070412,<20070420 or >20070412-20070420.
Alternative modes of fine-tuning visit timing are with SYNFREQ
and with phase blocking.
Keyword controlling the cadence of visits. #-# is the absolute minimum
and requested maximum number of nights cadence from one visit to the next.
The result will be a typical visit spacing in that range, but sometimes
longer due to constraints, weather, or queue competition.
If the SYNFREQ minimum symbol is 0 day and the target has more than one track
in the night, we will assume that the target may potentially be observed on
both tracks.
If the SYNFREQ minimum symbol is 1 day, we will assume that the target may be
observed on at most one track in the night, not two.
Leaving SYNFREQ blank implies that the target
may potentially be observed on more than one track per night. If instead
it is intended to limit the cadence to at most one visit per night,
use either the keyword SYNFREQ (with minimum symbol 1) or use
the keyword SYNDATE (with e.g. the =date formalism) to enforce this.
Lacking such indication, the RA potentially may validly observe
a target on both tracks within one night by default.
By this convention the RA is relieved of continually rechecking
on previously observed tracks and can simply rely on software that prevents
unwanted intra-night repeat visits via the SYNFREQ or SYNDATE keywords.
Alternative modes of fine-tuning visit timing are with SYNDATE =date
strings, and with phase blocking.
A string Y or N to state whether a telluric standard is required. In addition, for planet search work sometimes the PI seems to want a telluric with a different GC configuration than that of the target we have added GC1, GC0, GCboth to cover these conditions and ensure that we get the standard with the configuration that the PI needs.
Number of thorium-argon wavelength calibration lamps to be obtained
during twilight (when standard cals are taken) in addition to any STDCALS or EXTRACALS ThAr
comparison arcs.
Exposure time will be the default for the current setup; otherwise
use EXTRACALS.
Number of visits to execute for a given target. Note that a single science object can have multiple "targets," viz. entries in the htopx database.
Each target can have multiple visits. Each visit can have multiple CRSPLIT
exposures, adding up to the specified total exposure time.
*HRES+HET delivers very little flux below 4000 Å
**HRS+HET delivers very little flux above 10400 Å
K suffix means an extra focus offset is used for the blue
end of the spectrograph (down near the Ca II K line)
These values set the rotation of the cross disperser to:
select which orders fall on the CCD
set how much inter-order space there is for sky fibers
The three wavelengths given above for each value of CrossDisp are the blaze (central) wavelengths of the blue-most
order, the central order that falls between the two CCDs, and the red-most order.
The wavelengths given are for the echelle=central setting.
The shortest wavelength observable is 400nm, set by the filter for rejecting the 2nd order of the cross disperser, and by the HRS image
quality (as specified and designed).
The longest wavelength observable is approximately 1050nm due to the drop in the CCD quantum efficiency.
The central wavelength of any order can be calculated from any other order of known central wavelength
and order number (e.g. those in the table) by using the relationship.
lambda * order = constant
e.g. for 316g4931, where lambda=4931 and order=124, the central wavelength of order 150 is (4931*124)/150=4076.
The spectral coverage of a given order (its FSR or Free Spectral Range) is lambda/order number. eg. 316g4931: for order
124, lambda=4931 so FSR=39.8 Å
A filter is always used for rejecting the 2nd order of the cross disperser, and it is selected automatically.
