VOTable 1.5
  description: SP_ACE computes stellar parameters (gravity, temperature) and element abundances from optical stellar spectra (`sample spectrum`_). It employs 1D stellar atmosphere models in Local Thermodynamic Equilibrium (LTE). The present service does not offer all the options available for SP_Ace as documented in `the tutorial`_. All options are available if running SP_Ace locally (cf. `download page`_). This service exposes an updated version containing some bug fixes with respect to the one described in the paper. .. _the tutorial: http://dc.g-vo.org/sp_ace/q/dist/static/tutorial.pdf .. _download page: http://dc.g-vo.org/sp_ace/q/dist/static .. _sample spectrum: http://dc.g-vo.org/sp_ace/q/c/static/fast_spectrum.txt
INFO legal = If you use results obtained by this service, please cite the original publication (see source meta) and acknowlege: This work has made use of the sp_ace spectral analysis tool version 1.4.
RESOURCE (meta)
INFO serviceInfo = http://dc.g-vo.org/sp_ace/q/c/api? | SP_ACE spectral analysis tool
INFO QUERY_STATUS = OK | OK
INFO server_software = DaCHS/2.12.2 twistedWeb/22.4.0 | Software that produced this VOTable
INFO server = http://dc.g-vo.org | Base URI of the server
INFO citation = http://dc.g-vo.org/sp_ace/q/c/howtocite | Advice on citing this resource
INFO publication_id = 2016A&A...587A...2B | A bibliographic source citable for (parts of) this data
INFO ivoid_service = ivo://org.gavo.dc/sp_ace/q/c | Originating VO service
INFO publisher = The GAVO DC team | Data centre that has delivered the data
INFO rights = If you use results obtained by this service, please cite the original publication (see source meta) and acknowlege: This work has made use of the sp_ace spectral analysis tool version 1.4. | Legal conditions applicable to (parts of) the data contained
INFO request_date = 2026-08-06T13:28:55Z
INFO contact = gavo@ari.uni-heidelberg.de | Contact option
INFO reference_url = http://dc.g-vo.org/sp_ace/q/c/info | More information on the data Source
INFO creator = Boeche, C. | Name of a person or entity that produced a contributing resource
INFO creator = Demleitner, M. | Name of a person or entity that produced a contributing resource
INFO creator = Heinl, H. | Name of a person or entity that produced a contributing resource
PARAM INPUT:UPLOAD |  | char[*] |  |  | An upload of the form 'spectrum,URL'; the input for this parameter is then taken from URL, which may be param:name for pulling the content from the inline upload name. Purpose of the upload: ASCII file with two columns: wavelength (in Angstrom) and continuum normalized flux. The spectrum must be radial velocity corrected (wavelengths in rest frame). The spectral resolution power should be between 2000 and 20000. SP_Ace handles spectra in the stellar parameters intervals Teff=[3600,7400]K, logg=[0.2,5.0], [M/H]=[-2.4,0.4]dex.
PARAM INPUT:fwhm = 0.4 | Angstrom | float | spect.line.width;instr |  | Starting value for estimation of FWHM of the instrument line profile.
PARAM INPUT:wave_lims = 4800 6860 |  | char[*] |  |  | Give up to five wavelength intervals you want to analyze, starting from the lowest. Intervals not covered by the library will be ignored. The default setting is the range of wavelenghts currently processed by the software.
PARAM INPUT:tforce | K | float | stat.param;phys;temperature.effective |  | Force solver to assume this temperature. Leave empty to let SP_Ace estimate this parameter.
PARAM INPUT:gforce |  | float | stat.param;phys.gravity |  | Force solver to assume this gravity. Leave empty to let SP_Ace estimate this parameter.
PARAM INPUT:snrforce |  | float | stat.param;stat.snr |  | Force solver to assume this signal to noise ratio on every pixel. Suggestion: Leave empty to let SP_Ace to estimate this parameter pixel-by-pixel.
PARAM INPUT:rv_ini | km/s | float | spect.dopplerVeloc |  | Provide an estimation of the object's radial velocity in case the spectrum is not RV-corrected.
PARAM INPUT:compute_errors |  | boolean |  |  | Make SP_Ace estimate errors (this increases runtime significantly).
PARAM INPUT:alpha |  | boolean |  |  | If selected, the output will only contain two abundances: 'alphas' and 'metals', which are the estimation of the abundances of alpha-process elements and non-alpha-process elements as if they were one element. Hint: This option is mostly useful with low-resolution (R ~ 2000) spectra. See the tutorial for more details.
PARAM INPUT:no_norm |  | boolean |  |  | Process the spectrum with the normalization provided by the user? This option switches off the internal re-normalization done by SP_Ace. Suggestion: Do not set unless you are absolutely sure that your normalization is right.
PARAM INPUT:norm_rad = 30 |  | float |  |  | This parameter determines the flexibility of the curve used to fit the continuum during the re-normalization of the spectrum. The higher the number the more rigid the curve is (see discussion in the tutorial and in Sec.7.4 of the paper). Suggestion: leave the default value unless you know very well what you are doing.
PARAM INPUT:abd_loop |  | boolean |  |  | Switch on the loop that iteratively derives stellar parameters (Teff, log g, [M/H]) and chemical abundances. Suggestion: do not set (see Sec. 8.5.1 of the paper). If your spectrum has low resolution (R ~ 2000), see discussion in the tutorial.
PARAM INPUT:RESPONSEFORMAT |  | char[*] | meta.code.mime |  | File format requested for output. | values: Tab separated values=text/tab-separated-values; Alias for Tab separated values=tsv; Fixed-column plain text=text/plain; Alias for Fixed-column plain text=txt; CSV without column labels=text/csv; Alias for CSV without column labels=csv_bare; CSV with column labels=text/csv;header=present; Alias for CSV with column labels=csv; JSON=application/json; Alias for JSON=json; GeoJSON=application/geo+json; Alias for GeoJSON=geojson; Default VOTable=application/x-votable+xml; Alias for Default VOTable=votable; Binary2 VOTable=application/x-votable+xml;serialization=binary2; Alias for Binary2 VOTable=votable/b2; Alias for Binary2 VOTable=votableb2; Tabledata VOTable=application/x-votable+xml;serialization=tabledata; Alias for Tabledata VOTable=text/xml; Alias for Tabledata VOTable=votable/td; Alias for Tabledata VOTable=votabletd; Tabledata VOTable version 1.1=application/x-votable+xml;serialization=tabledata;version=1.1; Alias for Tabledata VOTable version 1.1=text/xml; Alias for Tabledata VOTable version 1.1=votabletd1.1; Tabledata VOTable version 1.1=application/x-votable+xml;version=1.1; Alias for Tabledata VOTable version 1.1=text/xml; Alias for Tabledata VOTable version 1.1=votable1.1; Tabledata VOTable version 1.2=application/x-votable+xml;serialization=tabledata;version=1.2; Alias for Tabledata VOTable version 1.2=text/xml; Alias for Tabledata VOTable version 1.2=votabletd1.2; VOTable version 1.6 beta, tabledata=application/x-votable+xml;serialization=tabledata;version=1.6; Alias for VOTable version 1.6 beta, tabledata=vodml; VOTable version 1.6 beta=application/x-votable+xml;version=1.6; Alias for VOTable version 1.6 beta=vodmlb; HTML=text/html; Alias for HTML=html; FITS Binary Table=application/fits; Alias for FITS Binary Table=fits
PARAM INPUT:MAXREC |  | int |  |  | Maximum number of records returned. Pass 0 to retrieve service parameters.
PARAM INPUT:VERB |  | int |  |  | Exhaustiveness of column selection. VERB=1 only returns the most important columns, VERB=2 selects the columns deemed useful to the average user, VERB=3 returns a table with all available columns. | values: terse=1; normal=2; everything=3
TABLE results
FIELD element |  | char[*] | phys.atmol.element |  | Element symbol
FIELD ab |  | float | phys.abund |  | Element abundance, logarithm of particle number relative to 1e12 H particles.
FIELD ab_low |  | float | phys.abund |  | Lower limit of 68% confidence interval of element abundance
FIELD ab_up |  | float | phys.abund |  | Upper limit of 68% confidence interval of element abundance
FIELD nlines |  | int | stat.fit.param |  | Number of lines evaluated for this element.
PARAM OUTPUT:teff | K | float | phys.temperature.effective |  | Effective Temperature of the best-fit modelled spectrum.
PARAM OUTPUT:teff_low | K | float | stat.error;phys.temperature.effective;stat.min |  | Lower limit of 68% confidence interval of Effective Temperature
PARAM OUTPUT:teff_up | K | float | stat.error;phys.temperature.effective;stat.max |  | Upper limit of 68% confidence interval of Effective Temperature
PARAM OUTPUT:logg | cm/s**2 | float | phys.gravity |  | Log of gravity of the best-fit modelled spectrum.
PARAM OUTPUT:logg_low | cm/s**2 | float | stat.error;phys.gravity;stat.min |  | Lower limit of 68% confidence interval of Log of gravity
PARAM OUTPUT:logg_up | cm/s**2 | float | stat.error;phys.gravity;stat.max |  | Upper limit of 68% confidence interval of Log of gravity
PARAM OUTPUT:metals | dex | float | phys.abund.Z |  | Metallicity of the best-fit modelled spectrum.
PARAM OUTPUT:metals_low | dex | float | stat.error;phys.abund.Z;stat.min |  | Lower limit of 68% confidence interval of Metallicity
PARAM OUTPUT:metals_up | dex | float | stat.error;phys.abund.Z;stat.max |  | Upper limit of 68% confidence interval of Metallicity
PARAM OUTPUT:conv |  | short | meta.code;stat.fit |  | 0 if solution converged, otherwise an error flag (see note or table 1 in the tutorial).
PARAM OUTPUT:rv | km/s | float | stat.fit |  | Empirical adjustment for RV (obtained by optimizing line overlap).
PARAM OUTPUT:fwhm | Angstrom | float | spect.line.width;instr |  | A posteriori full width half maximum of the instrument profile.
PARAM OUTPUT:snr |  | float | stat.snr |  | Estimated signal to noise ratio of incoming spectrum.
PARAM OUTPUT:chisq |  | float | stat.fit.chi2 |  | χ² between incoming and modelled spectrum.
