Dusty Supernovae Running the Thermodynamics of the Matter Reinserted Within Young and Massive Super Stellar Clusters

Abstract

Following the observational and theoretical evidence that points at core-collapse supernovae (SNe) as major producers of dust, here we calculate the hydrodynamics of the matter reinserted within young and massive super stellar clusters under the assumption of gas and dust radiative cooling. The large SN rate expected in massive clusters allows for a continuous replenishment of dust immersed in the high temperature thermalized reinserted matter and warrants a stationary presence of dust within the cluster volume during the type II SN era. We first show that such a balance determines the range of the dust-to-gas-mass ratio, and thus the dust cooling law. We then search for the critical line that separates stationary cluster winds from the bimodal cases in the cluster mechanical luminosity (or cluster mass) versus cluster size parameter space. In the latter, strong radiative cooling reduces considerably the cluster wind mechanical energy output and affects particularly the cluster central regions, leading to frequent thermal instabilities that diminish the pressure and inhibit the exit of the reinserted matter. Instead, matter accumulates there and is expected to eventually lead to gravitational instabilities and to further stellar formation with the matter reinserted by former massive stars. The main outcome of the calculations is that the critical line is almost two orders of magnitude or more, depending on the assumed value of V A∞ , lower than when only gas radiative cooling is applied. And thus, many massive clusters are predicted to enter the bimodal regime.

The Formation of Secondary Stellar Generations in Massive Young Star Clusters From Rapidly Cooling Shocked Stellar Winds

“…The process of mass accumulation in star clusters with a bimodal solution was explored by Wünsch et al (2008) who ran 2D hydrodynamic simulations and found that parcels of the hot gas below the stagnation radius cool rapidly from ∼ 10 7 K down to the minimum allowed temperature 10 4 K (motivated by the assumption that the gas is ionized by stellar radiation) and are subsequently compressed by the surrounding hot gas until they reach pressure equilibrium as dense warm clumps. The bimodal solution was further studied by Tenorio-Tagle et al (2010) who estimated the shapes of recombination line profiles from 2D simulation, Silich et al (2010) who applied it to high-redshift SCUBA galaxies with extremely high star formation rates, Hueyotl-Zahuantitla et al (2010 who applied it to galactic nuclear star clusters, Wünsch et al (2011) who calculated the time evolution of clusters evolving in the bimodal regime for the whole period of the existence of massive stars, and Tenorio-Tagle et al (2013) who included cooling due to dust produced by supernovae.…”

The full evolution of supernova remnants in low- and high-density ambient media

“…The results obtained here can contribute to the understanding of dust formation and evolution at early stages of the Universe, when most of the dust grains are expected to be formed in the supernovae ejecta (e.g. Todini & Ferrara 2001, Marchenko 2006, Bianchi & Schneider 2007, Tenorio-Tagle et al 2013). Indeed, recent calculations suggest that in low ambient gas densities (n0 < 100 cm −3 ), just a small fraction (about 10% − 20%) of dust grains could survive crossing the reverse shock (e.g.…”

ON THE ORIGIN OF THE ABSORPTION AND EMISSION LINE COMPONENTS IN THE SPECTRA OFPHL 293B

“…The above relations yield a shocked gas temperature T S = 5.2 × 10 7 K and a shocked gas density n S ∼ 2×10 3 cm −3 . These, together with the value of the cooling rate, Λ ∼ 10 −20 erg cm 3 s −1 (see Figure 2 of Tenorio-Tagle et al 2013) lead to the cooling time:…”