TY - JOUR
T1 - Near-infrared adaptive optics imaging of infrared luminous galaxies
T2 - the brightest cluster magnitude-star formation rate relation
AU - Randriamanakoto, Z.
AU - Escala, A.
AU - Väisänen, P.
AU - Kankare, E.
AU - Kotilainen, J.
AU - Mattila, S.
AU - Ryder, S.
PY - 2013/10/1
Y1 - 2013/10/1
N2 - We have established a relation between the brightest super star cluster (SSC) magnitude in a galaxy and the host star formation rate (SFR) for the first time in the near-infrared (NIR). The data come from a statistical sample of ∼40 luminous IR galaxies (LIRGs) and starbursts utilizing K-band adaptive optics imaging. While expanding the observed relation to longer wavelengths, less affected by extinction effects, it also pushes to higher SFRs. The relation we find, MK ∼ -2.6log SFR, is similar to that derived previously in the optical and at lower SFRs. It does not, however, fit the optical relation with a single optical to NIR color conversion, suggesting systematic extinction and/or age effects. While the relation is broadly consistent with a size-of-sample explanation, we argue physical reasons for the relation are likely as well. In particular, the scatter in the relation is smaller than expected from pure random sampling strongly suggesting physical constraints. We also derive a quantifiable relation tying together cluster-internal effects and host SFR properties to possibly explain the observed brightest SSC magnitude versus SFR dependency.
AB - We have established a relation between the brightest super star cluster (SSC) magnitude in a galaxy and the host star formation rate (SFR) for the first time in the near-infrared (NIR). The data come from a statistical sample of ∼40 luminous IR galaxies (LIRGs) and starbursts utilizing K-band adaptive optics imaging. While expanding the observed relation to longer wavelengths, less affected by extinction effects, it also pushes to higher SFRs. The relation we find, MK ∼ -2.6log SFR, is similar to that derived previously in the optical and at lower SFRs. It does not, however, fit the optical relation with a single optical to NIR color conversion, suggesting systematic extinction and/or age effects. While the relation is broadly consistent with a size-of-sample explanation, we argue physical reasons for the relation are likely as well. In particular, the scatter in the relation is smaller than expected from pure random sampling strongly suggesting physical constraints. We also derive a quantifiable relation tying together cluster-internal effects and host SFR properties to possibly explain the observed brightest SSC magnitude versus SFR dependency.
KW - galaxies: star clusters: general
KW - galaxies: star formation
KW - infrared: galaxies
UR - http://www.scopus.com/inward/record.url?scp=84884857630&partnerID=8YFLogxK
U2 - 10.1088/2041-8205/775/2/L38
DO - 10.1088/2041-8205/775/2/L38
M3 - Article
AN - SCOPUS:84884857630
VL - 775
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
SN - 2041-8205
IS - 2
M1 - L38
ER -