2026A&A...706A.370B -
Astronomy and Astrophysics, volume 706A370 (2026/2-1)
The stellar initial mass function of nearby young moving groups.
BERTOLOTTO-STEFANELLI R., DOWNES J.J., SUAREZ G., MATEU C., GAGNE J. and ROMAN-ZUNIGA C.
Abstract (from CDS):
Context. The solar neighbourhood is populated by nearby (<200 pc), young (<100 Myr) moving groups (NYMGs) of stars, whose origins are still a matter of debate. One plausible explanation is that they are remnants of individual stellar clusters and associations that are currently dispersing throughout the galactic disc.
Aims. We aim to derive the initial mass function (IMF) of a large sample of NYMGs.
Methods. We developed and applied an algorithm that uses photometric and astrometric data from Gaia DR3 to detect NYMGs as over-densities in a kinematic space, whose members distribute along young isochrones. We inferred individual masses from the photometry of both the detected and the previously known candidates. We estimated the IMFs for 33 groups, 30 of them for the first time, in an average mass range 0.1 < m/M⊙ < 5, with some groups going as low as 0.02 M⊙ and as high as 10 M⊙. We parameterised these IMFs using a log-normal for m < 1 M⊙ and a power-law for m > 1 M⊙.
Results. We detected 4166 source candidate members of 44 known groups, including 2545 new candidates. We recovered 44-54% of the literature candidates and estimated a contamination rate from old field stars of 16-24%. The candidates of the detected groups distribute along young isochrones, which suggests that they are potential members of NYMGs. Parameterisations of both the average of the 3 3 IMFs based on our detections (mc = 0.25 ± 0.17 M⊙, σc = 0.45 ± 0.17, and α = -2.26 ± 0.09) and the one based on the known candidates from the literature (mc = 0.22 ± 0.14 M⊙, σc = 0.45 ± 0.17, and α = -2.45 ± 0.06) are in agreement with the IMF parameterisation of the solar neighbourhood and young stellar associations.
Conclusions. Our parameterisation of the average IMF, together with the distribution of the detected group members along young isochrones offer strong evidence suggesting that the NYMGs are remnants of individual stellar associations and clusters. We confirm that there are no systematic biases in our detection and in the literature in the range of 0.1 < m/M⊙ < 10.
Abstract Copyright:
© The Authors 2026
Journal keyword(s):
open clusters and associations: general - solar neighborhood - Galaxy: structure
VizieR on-line data:
<Available at CDS (J/A+A/706/A370): members.dat table1.dat>
Status at CDS
:
Tables of objects will be appraised for possible ingestion in SIMBAD.
Simbad objects:
16
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2026A&A...706A.370B and select 'bookmark this link' or equivalent in the popup menu