MUSE_STANDARD(7)

📦
version 2.8.7 · 2 versions
, in debian bookworm, ubuntu noble

🌸 MUSE_STANDARD(7) 🌸

okay bestie, welcome to MUSE_STANDARD(7) — this one lives in the muse recipes section of the manual, and it's the whole glow-up guide for muse_standard. grab a snack, we're getting into it 💖

✨ NAME ✨

muse_standard — create a flux response curve from a standard star exposure. that's the entire assignment, no cap 💅

🦋 SYNOPSIS 🦋

esorex muse_standard [OPTIONS] FILE.sof

🎀 DESCRIPTION 🎀

so here's the vibe. first, it merges the pixel tables from all the IFUs and corrects for differential atmospheric refraction when that's actually necessary. then, to derive the flux response curve, it integrates the flux of every object it detects inside the field of view, using the profile you gave it.

next it picks one object to be the standard star — either the brightest one or the one nearest to you, depending on --select — and compares that star's measured fluxes against tabulated fluxes to work out the sensitivity over wavelength. then it postprocesses that sensitivity curve to mark the wavelength ranges that are affected by telluric absorption, interpolates over those telluric regions, and derives a telluric correction spectrum for them.

after that the final response curve gets linearly extrapolated out to the largest possible MUSE wavelength range and smoothed using whatever method --smooth says. heads up though: the derivation of the telluric correction spectrum assumes the star has a smooth spectrum within the telluric regions. so, like, if your star is doing something weird in there, that's on the star.

if there's more than one exposure in the input data, the derivation of the flux response and the telluric corrections happens separately for each exposure. and for each exposure, an image containing the extracted stellar spectra plus the datacube used for flux integration both get saved, together with collapsed images for every filter you asked for.

now, the profile tea 🍵 — in MUSE's WFM data (both AO and non-AO), the Moffat profile is a genuinely good approximation of the actual PSF. using the smoothed profile ("smoffat") helps bump up the S/N and in most cases removes systematics entirely. in NFM, though? the profile is a combination of a wide PSF plus the central AO-corrected peak, and that cannot be fit well by an analytical profile at all 😭. in that case the circular aperture is the best way to extract the flux. and using --profile="auto" (which is the default, bestie) selects these options to give you the best flux extraction for most cases. it's giving "we already thought about it for you" energy 👑

💖 OPTIONS 💖

  • --profile <str> — the type of flux integration to use. "gaussian", "moffat" and "smoffat" all do 2D profile fitting. "circle" and "square" are non-optimal aperture flux integrators (yes, that's the official read). "smoffat" smooths the Moffat parameters from an initial fit, so it can derive physically meaningful wavelength-dependent behavior. "auto" picks the smoothed Moffat profile for WFM data and circular flux integration for NFM. (str; default: auto). the full name of this option for the EsoRex configuration file is muse.muse_standard.profile [default = auto].
  • --select <str> — how to pick the star for flux integration. "flux" uses the brightest star in the field; "distance" uses the detection nearest to the approximate coordinates of the reference source. (str; default: distance). the full name of this option for the EsoRex configuration file is muse.muse_standard.select [default = distance].
  • --smooth <str> — how to smooth the response curve before it gets written to disk. "none" does no smoothing at all — and ngl, a response curve like that is only useful if you're going to smooth it externally. "median" does a median-filter of 15 Angstrom half-width. "ppoly" fits piecewise cubic polynomials (each one across 2x150 Angstrom width), postprocessed by a sliding average filter of 15 Angstrom half-width. (str; default: ppoly). the full name of this option for the EsoRex configuration file is muse.muse_standard.smooth [default = ppoly].
  • --lambdamin <float> — cut off the data below this wavelength after loading the pixel table(s). (float; default: 4000.0). the full name of this option for the EsoRex configuration file is muse.muse_standard.lambdamin [default = 4000.0].
  • --lambdamax <float> — cut off the data above this wavelength after loading the pixel table(s). (float; default: 10000.0). the full name of this option for the EsoRex configuration file is muse.muse_standard.lambdamax [default = 10000.0].
  • --lambdaref <float> — reference wavelength used for correction of differential atmospheric refraction. the R-band (peak wavelength ~7000 Angstrom), which is the one usually used for guiding, sits close to the central wavelength of MUSE, so a value of 7000.0 Angstrom should be used if nothing else is known. a value less than zero switches DAR correction off. (float; default: 7000.0). the full name of this option for the EsoRex configuration file is muse.muse_standard.lambdaref [default = 7000.0].
  • --darcheck <str> — carry out a check of the theoretical DAR correction using source centroiding. if it's "correct" it will also apply an empirical correction. (str; default: none). the full name of this option for the EsoRex configuration file is muse.muse_standard.darcheck [default = none].
  • --filter <str> — the filter name(s) to use for the output field-of-view image. each name has to correspond to an EXTNAME in an extension of the FILTER_LIST file. if you give an unsupported filter name, the creation of that respective image is just... omitted 🙈. if you give multiple filter names they have to be comma separated. and if you want the zeropoint QC parameters, make sure you add "Johnson_V,Cousins_R,Cousins_I". (str; default: white). the full name of this option for the EsoRex configuration file is muse.muse_standard.filter [default = white].
ok also, quick note bestie: you can create a configuration file containing these options along with suitable default values. just refer to the details provided by the 'esorex --help' command. 🫶

🌈 SEE ALSO 🌈

  • the full documentation for the muse pipeline can be downloaded as a PDF file using this URL:
ftp://ftp.eso.org/pub/dfs/pipelines/muse/muse-pipeline-cookbook-2.8.7.pdf

⭐ VERSION ⭐

muse_standard 2.8.7

👑 AUTHOR 👑

Peter Weilbacher <https://support.eso.org>

🫶 BUG REPORTS 🫶

please report any problems to https://support.eso.org. alternatively, you may send a report to the ESO User Support Department <usd-help@eso.org>. they want to hear from you, fr fr 💌

💜 LICENSE 💜

this file is part of the MUSE Instrument Pipeline Copyright (C) 2005, 2019 European Southern Observatory

this program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

this program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. see the GNU General Public License for more details.

you should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02111-1307 USA

and that's the whole page bestie ✨ this one's from the muse recipes manual, version 2.8.7 — go make some flux response curves, you've absolutely got this 💖🦋🎀

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