zspec Comment Flags

This document explains the standard comments which can be assigned to a spectrum processed with zspec.

General comments

agn: use only for objects with clearly broad lines; includes qso's
offser: offset serendip: check first that this is not just a second object on slit; you do this by looking at the following object (pressing "next"), and verifying that the slit number does not change. If the slit number changes, then there is a bona-fide serendip in the slit. If only one line is visible, use offser sngl. Do not attempt to actually measure the second redshift; this will be done in a separate second pass.
z=xx: enter a forced-z value in the comments. Such cases are automatically Q=2.

Q=2 qualifiers

All Q=2's should have at least one of the following in the comments:

supser: superimposed serendip; two redshifts in one spectrum; if only one line, use supser sngl; adopt either z for entering into zspec file; do not attempt to measure the second z; all supser's get Q=2 (see above)
marg: redshift is doubtful because S/N is low; features barely visible
sngl: single emission line only; in this case add the suspected line ID. Example: sngl, 6563
bs: bad sky subtrac; could be due to bad OH lines or bad continuum
bcont: bad continuum, usually due to bad sky subtr or bcol
disc: use with bcont (bcont disc) to denote special cases in which there is a jump in intensity across the CCD gap
bext: extraction window is misplaced vertically or is too wide or too narrow or is contaminated by a companion
edge: close to slit edge and possibly messed up on that account

Other quality-related comments

the extracted 1-d spectrum may be adequate for a redshift (as indicated by the Q code) but there is something wrong that makes it an unreliable INTEGRATED SPECTRUM of the galaxy and therefore possibly unsuitable for further analyses such as EWs, rotation curves, linewidths, SEDs. Examples include:

bad extraction window, gets only part of galaxy or is contaminated by companion
emission extends beyond extraction window
flux discontinuity at CCD boundary (due to bad extraction windows and consequent bad sky subtraction)

Use iffy for Q=3 and Q=4 only. Iffy can be further qualified if desired by adding bs, bcont, disc, bext, or edge. Note: IFFY APPLIES TO INTEGRATED SPECTRA, NOT REDSHIFTS! REDSHIFTS ARE DESCRIBED BY Q-CODES.

fix

this flags bad reductions that look like they could be fixed with further attention. Basically, this is a flag for Jeff to look at the reductions. This will force a relook.