J/A+A/703/A295ivo://CDS.VizieR/J/A+A/703/A295CDSSiljeg B.Adams E.A.K.Fraternali F.Hess K.M.Marasco A.Denes H.,Garrido J.Lucero D.M.Morganti R.Sanchez-Exposito S.,van der Hulst J.M.2026-03-02T06:25:50Z2025-11-26T08:28:11ZCDS support team

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

cds-question@unistra.frradio-galaxiesh-i-line-emissiongalaxiesradio-sourcesDwarf-dwarf galaxy encounters are a key aspect of galaxy evolution as they can ignite or temporarily suppress star formation in dwarfs and can lead to dwarf mergers. However, the frequency and impact of dwarf encounters remain poorly constrained due to limitations of spectroscopic studies, e.g. surface-brightness incompleteness of optical studies and poor spatial resolution of single-dish neutral hydrogen (HI) surveys. We aim to quantify the frequency of isolated gas-rich dwarf galaxy multiples using the untargeted, interferometric Apertif HI survey and study the impact of the interaction on star formation rates of galaxies as a function of the on-sky separation. Our parent dwarf sample consists of 2481 gas-rich galaxies with stellar masses 10^6^<M*/M_{sun}_<5*10^9^, for which we identify close companions based on projected separation (r_p_) and systemic velocity difference (Del_V_sys). We explore both constant thresholds for r_p_ and Del_V_sys corresponding to 150kpc and 150km/s on all galaxies in our sample, and mass-dependent thresholds based on a stellar-to-halo mass relation. We find the average number of companions per dwarf in our sample to be 13% (20%) when considering mass-dependent (constant) thresholds. In the stellar mass regime of 2*10^8^<M*/M_{sun}_<5*10^9^, we find a three times higher frequency (11.6%) of dwarf companions than previously determined from optical spectroscopic studies, highlighting the power of HI for finding dwarf multiples. Furthermore, we find evidence for an increase in star formation rates (SFRs) of close dwarf galaxy pairs of galaxies with similar stellar masses.2025A&A...703A.295Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/703/A295CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/667/A39 : APERTIF DR1 continuum source catalog (Kutkin+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/703/A295https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/703/A295http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/703/A295https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/703/A295https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/703/A295http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/703/A295GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/703/A295/dwarfs (Parent dwarf galaxy sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/703/A295/dwarfs?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/703/A295/dwarfs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/703/A295/dwarfs?GETtext/xml+votable180.050000true0.0886561131.022106110.0055555555555555564/59 62 652 657 5/191 234-235 418-419 424 426 533 576-577 580-581 592 594 598 600-602 604 624 768 1495 1502 1518 1525 1857 1860 2287 2540 2591 2599 2613-2614 2625 2632-2633 2635-2636 2638 2640 2642 2657-2658 2686 2694 2697 2702 2765 2776-2777 2779 2793-2795 2808 2810-2811 2814 2826 2844 3389-3391 3436 3458 3473 3475-3476 5092 5104 5107 6/759 762 922 928-930 934-935 971 991 1010-1013 1016 1019 1021-1023 1666-1667 1671 1682-1683 1688-1690 1700 1702-1703 1708 1710-1713 1715 1720 2128-2129 2131 2137 2271 2289 2291-2293 2297 2300 2313 2316-2317 2319 2328-2330 2332-2333 2349-2351 2353 2356 2360-2362 2365-2367 2372 2374-2375 2380 2382-2384 2386-2387 2389-2391 2396-2398 2412-2414 2420-2422 2424-2426 2436-2437 2449-2450 2452-2454 2457 2460 2464 2500 2797 2799 2811 3076 3078 3080-3081 5975 6005-6007 6012 6014 6042 6055 6061-6064 6066 6070 6097 6108-6110 7436-7437 7446 7448-7450 7452-7453 7455 9127 9132-9133 9135 9143-9144 9146-9147 9163 9184 9186-9187 9192 9950-9951 9973 10120-10122 10125 10130 10136 10138-10139 10148-10149 10151 10157 10168 10301-10303 10326-10327 10330-10334 10338 10344-10345 10347-10348 10350-10351 10356-10358 10361 10363 10385 10388-10389 10391 10460-10462 10464 10467-10468 10480-10481 10483 10496 10498 10509 10511 10536-10537 10539 10548-10549 10551 10556-10558 10566 10572 10574 10592 10594 10623 10625-10627 10636-10638 10640 10656 10708-10709 10711 10735 10738 10750 10761 10763 10766-10767 10771 10774-10775 10781 10784-10785 10787 10793 10795-10796 10798-10799 10803 10814 10883 10887 10889 10892 10896-10898 10999 11004-11006 11037 11039 11058-11059 11068 11076-11077 11082 11086-11087 11097-11099 11113 11126 11167 11169 11171 11185 11187 11189-11193 11195-11198 11211 11238-11239 11250-11251 11254 11260 11279 11290 11298-11301 11303 11308-11310 11312-11314 11319 11323 11325-11327 11329 11337-11338 11341-11342 11347 11355 11361-11365 11367-11369 11371-11372 11374-11375 11380 11392-11394 11409 11412-11413 11460-11461 11467 11469-11472 11474-11475 11489-11492 11496 11523-11524 12791 12795 12798-12799 13111 13137 13140 13142 13147-13148 13150 13152 13160 13162 13168-13169 13173 13177 13179 13191 13201-13202 13205-13206 13209 13214 13248 13255 13265 13273 13279 13287 13304 13367 13374 13410 13414 13419 13447 13453-13454 13458 13461 13466 13473-13474 13477 13481 13484 13486 13535 13551 13554-13555 13583 13589 13591 13594 13597 13605-13606 13612-13613 13619-13620 13622 13628-13629 13634-13635 13643 13645 13647-13648 13654 13656 13659 13663 13665 13667 13672-13673 13684 13688-13689 13709 13714-13715 13717-13718 13723 13735 13740 13743 13748 13751-13753 13755-13756 13759 13768-13769 13771 13791-13793 13795-13796 13798-13800 13803-13805 13813-13814 13825-13827 13830 13836 13857 13859 13862 13864 13866 13869-13871 13880 13882-13884 13886 13891 13899 13908-13910 13912-13914 13919 13921 13924-13926 13936 13941 13961 13965-13966 13977 14000 14036-14037 14039 14080-14081 14086-14087 14090 14093 14095-14096 14098 14100 14102-14103 14111 14118 14123-14124 14136 14138 14140 14144-14146 14153 14166 14172 14179 14184 14186 14208-14209 14212-14214 20330 20359 20372-20374 20376-20377 20381 20422-20426 20449 20452-20453 20457 20459 20461 20466 20472 20474 20478 28533 28539-28541 28543 28628https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/703/A295?format=asciiRadiodefaultJ/A+A/703/A295/dwarfsParent dwarf galaxy samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintApertifApertif name (1)meta.id;meta.maincharNgalmergNumber of galaxies in merged detections (2)meta.codecharRAJ2000Right ascension (J2000.0)degpos.eq.ra;meta.mainDEJ2000Declination (J2000.0)degpos.eq.dec;meta.mainVsysSystemic velocity of the galaxykm/sphys.veloc;src.class.starGalaxydoubleDistDistance to the galaxy (3)Mpcpos.distancefloate_DistError on the distance (4)Mpcstat.errorfloatlogMstarlog10 of Stellar masslog(solMass)phys.massfloate_logMstarUncertainty on logMstarlog(solMass)stat.errorfloatlogMHIlog10 of HI masslog(solMass)phys.massfloate_logMHIUncertainty on logMHIlog(solMass)stat.errorfloatlogSFR? log10 of Star formation ratelog(solMass.yr**-1)phys.SFRfloatnullablee_logSFR? Uncertainty on logSFRlog(solMass.yr**-1)stat.error;phys.SFRfloatnullable