DOGs are extremely red galaxies selected by their R - [24] color to be redder than most ultraluminous infrared galaxies at all redshifts. The formal selection is defined in Dey et al. (2008) as galaxies which satisfy the following two criteria: (1) F24µm ≥0.3 mJy, and (2) (R - [24]) ≥ 14 (Vega) mag. This corresponds to flux density ratios F24µm / FR ≥ 982. Pope et al. (2008b) later loosened the first criteria to accept galaxies of lower flux densities, i.e. F24µm ≥ 100 µJy.
DSFG is a generic term for star-forming galaxies which contain substantial amounts of dust or whose rest-frame optical/ultraviolet light might be significantly obscured. There is no strict observational definition for DSFGs, although the term has been used to refer to both extreme starbursts and more moderate star-forming galaxies.
Herschel-selected galaxies can refer to any galaxy selected in the Herschel PACS (100 µm, 160 µm) or SPIRE (250 µm, 350 µm, or 500 µm) bands. Casey et al. (2012a, b) define HSGs as galaxies detected at >3σ significance in at least one of the three SPIRE bands, where σ represents the instrumental and confusion noise uncertainty, so the detection criteria for HSGs are approximately S250 > 12 mJy, S350 > 14 mJy, and S500 > 15 mJy.
HyLIRGs (or HLIRGs) are defined as having 8-1000 µm luminosities between 1013 L⊙ and 1014 L⊙ .
LIRGs are defined as having 8-1000 µm luminosities between 1011 L⊙ and 1012 L⊙ .
Galaxies detected at millimeter wavelengths; this is a broad term which refers to SMG-like galaxies which are detected around 1 mm (ranging from ~ 850 µm-1.2 mm), as opposed to galaxies detected from 250-500 µm. MMG is also an alternate term for 'SMG.'
OFRGs are optically-faint (≲ 23) µJy radio galaxies which are not 850 µm-detected S850 ≲ 2-5 mJy Chapman et al., 2004a. OFRGs were originally proposed as an alternate class of dusty star-forming galaxy which are not luminous at 850 µm due to a temperature bias selection effect. The radio emission is thought to be dominated by star-formation and not AGN.
SFG is a generic term for normal star-forming galaxies which might include star-forming BzK galaxies, BX/BM galaxies, LBGs. SFGs exclude ULIRGs, SMGs, or other extreme starburst populations summarized in this review. Although the definition of SFG is not strictly defined in observational terms, several works have claimed that SFGs can be broadly described as sitting on the normal galaxy 'main sequence' (Noeske et al., 2007b) and are mostly not made up of secularly evolving, disk galaxies (Shapiro et al., 2008, Förster Schreiber et al., 2009, Tacconi et al., 2010, Daddi et al., 2010a, Genzel et al., 2010).
SFRGs are submillimeter-faint µJy radio galaxies like OFRGs, although unlike OFRGs, SFRGs need not be optically faint. SFRGs were described in Casey et al. (2009a) as an updated classification to OFRGs; since many SMGs are not optically faint (i > 23), removing the optically-faint classification from submillimeter-faint galaxies was necessary to estimate how many dusty galaxies were missing from Scuba surveys in the pre-Herschel era.
SMGs were initially defined as galaxies detected at 850 µm with the Scuba instrument at the James Clerk Maxwell Telescope (JCMT); they have flux densities S850 ≳ 2-5 mJy. More recently, the term 'SMG' has been used in a more broad sense to apply not only to galaxies luminous at 850 µm, but galaxies with continuum detections ≳ 1 mJy anywhere from ~ 250 µm-2 mm.
ULIRGs are defined as having 8-1000 µm luminosities between 1012 L⊙ and 1013 L⊙ .