We quantify the gas accretion rate from minor mergers onto star-forming galaxies in the local Universe using HI observations of 148 nearby spiral galaxies (WHISP sample). We developed a dedicated code that iteratively analyses HI data-cubes, finds dwarf gas-rich satellites around larger galaxies, and estimates an upper limit to the gas accretion rate. We found that 22% of the galaxies have at least one detected dwarf companion. We made the very stringent assumption that all satellites are going to merge in the shortest possible time, transferring all their gas to the main galaxies. This leads to an estimate of the maximum gas accretion rate of 0.28 M-circle dot yr(-1), about five times lower than the average star formation rate of the sample. Given the assumptions, our accretion rate is clearly an overestimate. Our result strongly suggests that minor mergers do not play a significant role in the total gas accretion budget in local galaxies.

Gas accretion from minor mergers in local spiral galaxies / DI TEODORO, ENRICO MARIA; FRATERNALI, FILIPPO. - In: ASTRONOMY & ASTROPHYSICS. - ISSN 0004-6361. - STAMPA. - 567:(2014), pp. 68-82. [10.1051/0004-6361/201423596]

Gas accretion from minor mergers in local spiral galaxies

DI TEODORO, ENRICO MARIA;
2014

Abstract

We quantify the gas accretion rate from minor mergers onto star-forming galaxies in the local Universe using HI observations of 148 nearby spiral galaxies (WHISP sample). We developed a dedicated code that iteratively analyses HI data-cubes, finds dwarf gas-rich satellites around larger galaxies, and estimates an upper limit to the gas accretion rate. We found that 22% of the galaxies have at least one detected dwarf companion. We made the very stringent assumption that all satellites are going to merge in the shortest possible time, transferring all their gas to the main galaxies. This leads to an estimate of the maximum gas accretion rate of 0.28 M-circle dot yr(-1), about five times lower than the average star formation rate of the sample. Given the assumptions, our accretion rate is clearly an overestimate. Our result strongly suggests that minor mergers do not play a significant role in the total gas accretion budget in local galaxies.
2014
567
68
82
DI TEODORO, ENRICO MARIA; FRATERNALI, FILIPPO
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1284371
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