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Introduction to the SOPHIE Archive

The SOPHIE Archive gives access to the observations obtained with the spectrograph since it started operations on 24 August 2006. Data enter the database one day after they are obtained. In its present version the database will produce, upon interrogation, a list of all existing observations for a given object or list of objects together with pointers to the extracted (e2ds) and reconnected (s1d) spectra, cross-corelation functions and radial velocity measurements, if public.
The above data are produced by the standard data reduction pipeline, executed immediately after the acquisition of the science exposures. The corresponding raw data can be downloaded as large tar files, containing all the observations and calibration taken in a given night. A continuing and long-standing curation effort aims at detecting, flaging and correcting any technical or observational signature that may affect the scientific usability of some observations. In particular, the targets identification is carefully checked. Any user's feedback that would contribute to identify issues and improve this vast corpus is highly welcome.

OHP data distribution policy

Access to SOPHIE observations is restricted to the original PI for a one-year period. However, some large key programs are granted an extended (5-year) protection. Spectra benefiting from this extension are released after a year, but in a modified form where the exact time of observation is truncated. The data will be available with all time information unmasked after the 5-year period.

Status of the Archive on 2 April 2017 :

The number of indexed spectra with valid identifiers now stands at 93586, corresponding to 6848 distinct object names. Currently 71604 spectra are fully public. In addition, 15643 spectra are available with the time information masked (5-year protection), and 6339 spectra are still under the normal 1-year embargo.

97431 CCF files exists for spectra with valid object names, corresponding to 6399 distinct objnames, only available for data which have cleared embargo.

Available information on spectra

The column headings on a query results page on spectra give the following information :
  • objname : Adopted designation for the object (see below)
  • coordinatesJ2000 : Corresponding equatorial coordinates (Jhhmmss.s±ddmmss)
  • S : Link to the SIMBAD database
  • E : Link to any spectra of this object listed in the ELODIE database
  • seq : A unique spectrum identifier (SOPHIE sequence No. x10; in case of an n-duplicate, we add n to seq)
  • date : Date of the observation (start of night)
  • mode : Mode used (High Efficiency or High Resolution)
  • fiber_b : use of second fiber (DARK, SKY, THAR)
  • exptime : Exposure time in seconds
  • sn26 : Signal-to-Noise ratio at center of order 26 (V-band)
  • view_spec : Display s1d spectrum, if released
  • view_head : Display FITS headers, if released
  • get_spec : Download s1d reconnected spectrum, if released
  • get_e2ds : Download e2ds extracted spectra (39 orders), if released
  • customize : Access to a page where customization of the available data is possible (some options not available).
  • search_ccf : Plot the CCF and view derived parameters.

Spectra are shown in order of increasing right ascension and then of sequence number (chronological order). At the present time, a simple way to list them by observing date is to replace in the URL the string "&ob=ra&" by "&ob=date&". See the instrument web page for more information and specially the data products page for a complete description of all files.

Available information on CCF results

  • seq : sequence number, a unique identifier for each SOPHIE exposure
  • objname : object identifier, chosen from a valid SIMBAD catalog
  • date : calendar date for the exposure
  • mask : spectral mask used for the CCF (F0,G2,K5,M4,M5)
  • rv : radial velocity, corrected to the barycenter of the Solar System (km/s)
    • ±err : estimated 1-σ error on CCF radial velocity, derived from contrast and FWHM, better for S/N < 100
  • fwhm : full width at half maximum of the CCF dip (km/s)
  • span : bisector velocity span, a measure of line asymmetry (km/s)
  • maxcpp : maximum number of counts/pixel in CCF (electrons)
  • contrast : contrast of CCF, expressed as percent depth of dip (%)
  • lines : number of absorption lines used to compute the CCF
  • view_head : display information contained in header of CCF file
  • get_ccf : download a 40-line FITS image (either 61 or 121 pixes wide) with the CCF computed for each order. Line 40 contains the average CCF. An accompanying ASCII file (not yet available) contains the individual radial velocities derived for e ach order.
  • view_ccf : plot of the average CCF over the entire 60 km/s velocity interval.

FITS extensions

Spectra of the second fiber (sky or Th-AR spectra) are included with the reconnected rebinned 's1d' spectra and with the extracted 'e2ds' spectra as FITS extensions. The 'e2ds' spectra also include extensions for the associated 'wave' and 'blaze' calibration files.

Advanced ways to access the Archive

If users need to download a large number of FITS files, details are given on the possibility of using direct access to the observation catalog, to 's1d' and 'e2ds' spectra and to 'ccf' files.

Flux calibration

At the present time SOPHIE spectra have a provisonal flux scale which is relative to the tungsten lamp, but the over-all instrumental flux modulation retains the characteristics of the uncorrected spectrum. In addition, 's1d' reconnected spectra suffer from a residual "echelle ripple" effect, amounting to 5 % in the HE and HR modes, corresponding to an undercorrected blaze function.

Object designations

There are currently nearly 6900 distinct object designations in the database. We are continuously searching and correcting mis-identifications, as part as the curation effort.

Any remaining errors should be reported to the database team.

updated on: 2 April 2017