Young massive star clusters: Achievements and challenges

In spite of significant recent and ongoing research efforts, most of the early evolution and long-term fate of young massive star clusters remain clouded in uncertainties. Here, I discuss our understanding of the initial conditions of star cluster formation and the importance of initial substructure for the subsequent dynamical-evolution and mass-segregation timescales. I also assess our current understanding of the (initial) binary fraction in star clusters and the shape of the stellar initial mass function at the low-mass end in the low-metallicity environment of the Large Magellanic Cloud. Finally, I question the validity of our assumptions leading to dynamical cluster mass estimates. I conclude that it seems imperative that observers, modellers and theorists combine efforts and exchange ideas and data freely for the field to make a major leap forward.Comment: 9 pages, 3 figures. Review talk. To appear in Proc. IAU Symp. 266 (Star clusters), eds. R. de Grijs and J. Lepin

Being a non-drinking student: an interpretative phenomenological analysis

Recent research suggests that safer student alcohol consumption might be assisted by understanding how social occasions are managed by non-drinkers. In-depth, semi-structured interviews with five 19-22 year old non-drinking English undergraduates were subjected to interpretative phenomenological analysis (IPA). We present five inter-linked themes: ‘living with challenges to non drinking’; ‘seeing what goes on in drinking environments’; ‘dealing with conversations about non-drinking (‘making excuses vs. coming out’)’; ‘knowing which friends care about you’; and ‘the importance of withholding “legroom” for peer pressure’. Participants felt under persistent peer scrutiny (as a form of peer pressure) and could feel alienated in drinking environments. Talking about non-drinking was characterised by whether to ‘come out’ (as a non-drinker) or ‘fake it’ (e.g., ‘I’m on antibiotics’). Loyal friendships were reported as particularly important in this context. The decision not to drink was experienced as providing a successful buffer to peer pressure for former drinkers. Our findings unsettle traditional health promotion campaigns which advocate moderate drinking among students without always suggesting how it might be most successfully accomplished, and offer tentative guidance on how non-drinking during specific social occasions might be managed more successfully. Findings are discussed in relation to extant literature and future research directions are suggested

How well do we know the age and mass distributions of the star cluster system in the Large Magellanic Cloud?

[ABRIDGED] The LMC star cluster system offers the unique opportunity to independently check the accuracy of age and mass determinations based on a number of complementary techniques, including isochrone analysis. Using our sophisticated tool for star cluster analysis based on broad-band spectral energy distributions (SEDs), we reanalyse the Hunter et al. (2003) LMC cluster photometry. Our main aim is to set the tightest limits yet on the accuracy of ABSOLUTE age determinations based on broad-band SEDs, and therefore on the usefulness of such an approach. Our broad-band SED fits yield reliable ages, with statistical absolute uncertainties within Delta[log(Age/yr)] = 0.4 overall. The systematic differences we find with respect to previous age determinations are caused by conversions of the observational photometry to a different filter system. The LMC's cluster formation rate (CFR) has been roughly constant outside of the well-known age gap between ~3 and 13 Gyr, when the CFR was a factor of ~5 lower. We derive the characteristic cluster disruption time-scale, log(t_4^dis/yr) = 9.9 +- 0.1, where t_dis = t_4^dis (M_cl/10^4 Msun)^0.62. This long characteristic disruption time-scale implies that we are observing the INITIAL cluster mass function (CMF). We conclude that the youngest mass and luminosity-limited LMC cluster subsets show shallower slopes than the slope of alpha = -2 expected (at least below masses of a few x 10^3 Msun), which is contrary to dynamical expectations. This may imply that the initial CMF slope of the LMC cluster system as a whole is NOT well represented by a power-law, although we cannot disentangle the unbound from the bound clusters at the youngest ages.Comment: 14 pages, 8 figures, resubmitted to MNRAS after responding to referee repor