J/A+A/625/A36ivo://CDS.VizieR/J/A+A/625/A36doi:10.26093/cds/vizier.36250036CDSWatkins A.E.Laine J.Comeron S.Janz J.Salo H.2019-05-13T13:50:06Z2019-05-07T08:36:39ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frgalaxiescatalogsgalaxy-classification-systemsUsing a sample of 175 low-inclination galaxies from the S^4^G, we investigate the origins of up-bending (Type III) breaks in the 3.6{mu}m surface brightness profiles of disk galaxies. We reanalyzed a sample of previously identified Type III disk break-hosting galaxies using a new, unbiased break-finding algorithm, which uncovered many new, sometimes subtle disk breaks across the whole sample. We classified each break by its likely origin through close examination of the galaxy images across wavelengths, and compare samples of galaxies separated by their outermost identified break types in terms of their stellar populations and local environments. We find that more than half of the confirmed Type III breaks in our sample can be attributed to morphological asymmetry in the host galaxies. As these breaks are mostly an artifact of the azimuthal averaging process, their status as physical breaks is questionable. Such galaxies occupy some of the highest density environments in our sample, implying that much of this asymmetry is the result of tidal disturbance. We also find that Type III breaks related to extended spiral arms or star formation often host down-bending (Type II) breaks at larger radius which were previously unidentified. Such galaxies reside in the lowest density environments in our sample, in line with previous studies that found a lack of Type II breaks in clusters. Galaxies occupying the highest density environments most often show Type III breaks associated with outer spheroidal components. We find that Type III breaks in the outer disks of galaxies arise most often through environmental influence: either tidal disturbance (resulting in disk asymmetry) or heating through, for example, galaxy harrassment (leading to spheroidal components). Galaxies hosting the latter break types also show bimodal distributions in central g-r color and morphological type, with more than half of such galaxies classified as Sa or earlier; this suggests these galaxies may be evolving into early-type galaxies. By contrast, we find that Type III breaks related to apparently secular features (e.g., spiral arms) may not truly define their hosts' outer disks, as often in such galaxies additional significant breaks can be found at larger radius. Given this variety in Type III break origins, we recommend in future break studies making a more detailed distinction between break subtypes when seeking out, for example, correlations between disk breaks and environment, to avoid mixing unlike physical phenomena.2019A&A...625A..36Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/625/A36CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/PASP/122/1397 : Spitzer Survey of Stellar Structure in Galaxies (Sheth+ 2010)J/A+A/569/A91 : Optical imaging for S4G (Knapen+, 2014)J/ApJS/217/32 : S4G galaxy morphologies in the CVRHS system (Buta+, 2015)J/A+A/582/A86 : Catalogue of features in the S4G (Herrera-Endoqui+, 2015)J/A+A/596/A25 : Disc breaks across masses and wavelengths (Laine+, 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/625/A36https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/625/A36http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/625/A36https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/625/A36https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/625/A36http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/625/A36GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/625/A36/table4 (Disk break parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/625/A36/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/625/A36/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/625/A36/table4?GETtext/xml+votable180.050000true76.9329167-62.990.0055555555555555566/664 697 4149 4446 5091 5134 5174 5241 5396 5399 5586 5589 5596 5599 5610 5617 5774 5793 5975 5977 5980 6034 6093 7234 7442 7485 7515 7536 7602 7704 7957 8001 8018 8195 8225 8287 8416 8506 9109 9437 10280 10475 10673 10740 10787 10841 10878 10901 10908 10912 10921 10925 11010 11207 11246 11379 11392 11401 11761 11801 11832 11947 12015 12030 16479 16845 17693 17717 18158 18209 18214 18425 18507 18800 19449 19611 19614 19667 22751 24902 24949 25078 25303 25439 25613 25715 25778 25887 25935 26113 26161 26175 26317 26343-26344 26349 26528 27098 27285 27525 27654 27668 27718-27719 27721 27736 27738 27765 27901 27917 27937 27943 27945 27948 27955 28044 28054 28058 28167 28201 28208 28213 28234 28258 28294 28299 28381 28416 28463 28529 28653 31323 31365 33143 33242 33954 33958 34494 34540 34554 34735 35746 35966 36056 36131 36134 36276 36300 36332 36450 36480 36648 36734 36789-36790 40791 43862 44635-44636 44809 44945 44998 46398 46429 46477 46479 46549 46577 46615 47456 48193https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/625/A36?format=asciiOpticaldefaultJ/A+A/625/A36/table4Disk break parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRprof2Display the radial profiles 2 datameta.ref.urlcharRprof1Display the radial profiles 1 datameta.ref.urlcharGalaxyGalaxy Namemeta.id;meta.maincharBtypeBreak classification (G1)meta.code.class;src.classcharRinInner radius boundaryarcsecphys.angSize;srcfloatRoutOuter radius boundaryarcsecphys.angSize;srcfloatRbr1? First break radiusarcsecphys.angSize;srcfloatnullableRbr2? Second break radiusarcsecphys.angSize;srcfloatnullableRbr3? Third break radiusarcsecphys.angSize;srcfloatnullablemuRbr1? Surface brightness at first break radiusarcsecphot.mag.sbfloatnullablemuRbr2? Surface brightness at second break radiusmag.arcsec**-2phot.mag.sbfloatnullablemuRbr3? Surface brightness at second break radiusmag.arcsec**-2phot.mag.sbfloatnullableh1Scale length of first disk segment (1)arcsecsrc.morph.scLengthfloath2? Scale length of second disk segment (1)arcsecsrc.morph.scLengthfloatnullableh3? Scale length of third disk segment (1)arcsecsrc.morph.scLengthfloatnullableh4? Scale length of fourth disk segment (1)arcsecsrc.morph.scLengthfloatnullablemu01Central surface brightness of first disk segment (1)mag.arcsec**-2phot.mag.sbfloatmu02? Central surface brightness of second disk segment (1)mag.arcsec**-2phot.mag.sbfloatnullablemu03? Central surface brightness of third disk segment (1)mag.arcsec**-2phot.mag.sbfloatnullablemu04? Central surface brightness of fourth disk segment (1)mag.arcsec**-2phot.mag.sbfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/A+A/625/A36/tablea1Radial profiles 1recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGalaxyGalaxy namemeta.id;meta.maincharRadRadius along major axisarcsecphys.angSizefloatmu36? Mean surface brightness at radius Radmag.arcsec**-2phot.mag.sbfloatnullableLoch? Local slope in surface brightness at radius Radarcsecstat.fit.paramdoublenullableSmoothloch? Median-smoothed version of Loch (1)arcsecstat.fit.paramdoublenullableA1m=1 Fourier mode amplitude at radius Radsrc.var.amplitudedoubleA2m=2 Fourier mode amplitude at radius Radsrc.var.amplitudedoubleJ/A+A/625/A36/tablea2Radial profiles 2recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGalaxyGalaxy namemeta.id;meta.maincharRadRadius along major axisarcsecphys.angSizefloatPA[0/360] Position angle of isophote major axisdegpos.posAngfloatdPA? Position angle of deprojected image isophote major axisdegpos.posAngfloatnullableEllEllipticity of isophote major axissrc.ellipticityfloatdEll? Ellipticity of deprojected image isophote major axissrc.ellipticityfloatnullableJ/A+A/625/A36/tablea3Detailed break justificationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintFname1Name of image file showing radial profiles of galaxy, in subdirectory imagesmeta.id;meta.filecharFname2Name of image file showing galaxy images, in subdirectory imagesmeta.id;meta.maincharGalaxyGalaxy namemeta.idcharMClassDetailed morphological classification of galaxy (1)srccharBtypeBreak classificationmeta.code.class;src.classcharL16BtypeBreak classification from Laine et al. (2016, Cat. J/A+A/596/A25) (G1)src.classcharNotesDetailed notes justifying Btypemeta.notechar