On the Heating Efficiency Derived From Observations of Young Super Star Clusters in M82

Silich, Sergiy; Tenorio-Tagle, G.; Torres-Campos, A.; Muñoz–Tuñón, C.; Monreal-Ibero, A.; Melo, V.

doi:10.1088/0004-637x/700/2/931

Cited by 18 publications

(24 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We found that massive clusters, like NGC 604 and NGC 595, should exhibit NIR-MIR excesses during a significant fraction of their evolution, especially if the heating efficiency of the thermalized matter is low as suggested by several independent studies (e.g. Smith et al 2006;Silich et al 2009). With regard to star clusters with masses of a few times ∼ 10 4 M ⊙ , we propose that the evolutionary trends of the NIR-MIR emission obtained from our models is well represented by NGC 592, NGC 592, IC 131 and IC 131-West, which have similar masses and their emission at wavelengths ≥ 10 µm is almost identical.…”

Section: Discussionsupporting

confidence: 54%

“…4. A low efficiency in the thermalization of the kinetic energy of stellar winds and supernova explosions (Silich et al 2007(Silich et al , 2009) would also alleviate the destruction of grains of all sizes.…”

Section: Discussionmentioning

confidence: 99%

“…Given a low heating efficiency, grain thermal sputtering is reduced as a consequence of a lower temperature in the shocked wind, alleviating the destruction of the population of small grains necessary to explain the NIR-MIR excesses. In favor of a low heating efficiency, first proposed by Smith et al (2006) and Larsen et al (2006), one can mention the work of Silich et al (2007Silich et al ( , 2009, who studied several young clusters in the central zone of M82. They found that the observed sizes and expansion velocities of the associated H ii regions are not consistent with the standard bubble model (Weaver et al 1977) which might be the result of a low heating efficiency ( 0.1).…”

Section: Star Cluster Wind Modelmentioning

confidence: 99%

See 2 more Smart Citations

Can Dust Injected by SNe Explain the NIR–MIR Excess in Young Massive Stellar Clusters?

Martínez-González

Wünsch

Palouš

2017

ApJ

View full text Add to dashboard Cite

We present a physically-motivated model involving the different processes affecting supernova dust grains as they are incorporated into the thermalized medium within young massive star clusters. The model is used to explain the near-to mid-infrared (NIR-MIR) excess found in such clusters and usually modeled as a blackbody with temperature ∼ (400 − 1000) K. In our approach, dust grains are efficiently produced in the clumpy ejecta of core-collapse supernovae, fragmented into small pieces ( 0.05 µm) as they are incorporated into the hot and dense ISM, heated via frequent collisions with electrons and the absorption of energetic photons. Grains with small sizes can more easily acquire the high temperatures (∼ 1000 K) required to produce a NIR-MIR excess with respect to the emission of foreground PAHs and starlight. However, the extreme conditions inside young massive clusters make difficult for these small grains to have a persistent manifestation at NIR-MIR wavelengths as they are destroyed by efficient thermal sputtering. Nevertheless, the chances for a persistent manifestation are increased by taking into account that small grains become increasingly transparent to their impinging ions as their size decreases. For an individual SN event, we find that the NIR-MIR excess last longer if the time required to incorporate all the grains into the thermalized medium is also longer, and in some cases, comparable to the characteristic interval between supernova explosions. Our models, can successfully explain the near-infrared excesses found in the star clusters observed in M33 (Relaño et al. 2016) assuming a low heating efficiency and mass-loading. In this scenario, the presence of the NIR-MIR excess is an indication of efficient dust production in SNe and its subsequent destruction.

show abstract

Section: Discussionsupporting

confidence: 54%

Section: Discussionmentioning

confidence: 99%

Section: Star Cluster Wind Modelmentioning

confidence: 99%

See 1 more Smart Citation

Can Dust Injected by SNe Explain the NIR–MIR Excess in Young Massive Stellar Clusters?

Martínez-González

Wünsch

Palouš

2017

ApJ

View full text Add to dashboard Cite

show abstract

“…The crucial parameter determining where the 2G stars form is the heating efficiency: if it is low (of order 1−10%), 2G stars form only in the center; if it is larger, 2G stars form everywhere throughout the cluster (see regions "compact 2G" and "extended 2G" on the parameter space map in Figure 10). The heating efficiency is closely related to the temperature of the hot shocked wind within the cluster and there is some observational evidence, that it may indeed be low (Silich et al 2009;Rosen et al 2014). This is interesting in terms of the aforementioned mass budget problem, because if 1G and 2G stars are spatially separated in this way, a substantial fraction of 1G stars can be lost due to the primordial gas expulsion and the subsequent dynamical evolution (Khalaj & Baumgardt 2016).…”

Section: Discussionmentioning

confidence: 94%

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

Wünsch

Palouš

Tenorio-Tagle

et al. 2017

ApJ

View full text Add to dashboard Cite

We study a model of rapidly cooling shocked stellar winds in young massive clusters and estimate the circumstances under which secondary star formation, out of the reinserted winds from a first stellar generation (1G), is possible. We have used two implementations of the model: a highly idealized computationally inexpensive spherically symmetric semi-analytic model, and a complex three-dimensional radiation-hydrodynamic simulations, and they are in a good mutual agreement. The results confirm our previous findings that in a cluster with 1G mass 10 7 M and half-mass radius 2.38 pc, the shocked stellar winds become thermally unstable, collapse into dense gaseous structures that partially accumulate inside the cluster, self-shield against ionizing stellar radiation and form the second generation (2G) of stars. We have used the semi-analytic model to explore a subset of the parameter space covering a wide range of the observationally poorly constrained parameters: the heating efficiency, η he , and the mass loading, η ml . The results show that the fraction of the 1G stellar winds accumulating inside the cluster can be larger than 50% if η he 10% which is suggested by the observations. Furthermore, for low η he , the model provides a self-consistent mechanism predicting 2G stars forming only in the central zones of the cluster. Finally, we have calculated the accumulated warm gas emission in the H30α recombination line, analyzed its velocity profile and estimated its intensity for super star clusters in interacting galaxies NGC4038/9 (Antennae) showing that the warm gas should be detectable with ALMA.

show abstract

“…The large central temperature depressions at the critical line and the slow acceleration of the reinserted matter within the cluster are indicative of the last stationary solution found before crossing the critical line. The presence of dust in the thermalized plasma within young SSCs provides a natural explanation for the observational and theoretical studies that have derived a strongly reduced mechanical energy output from some of the massive clusters in the galaxy M82 in order to account for the size of the compact H ii regions that surround them (see Smith et al 2006;Silich et al 2007Silich et al , 2009. Further evidence for the bimodal solution and the positive star formation feedback may come from the interpretation of the abundance variations from star to star in massive globular clusters (GC), such as ω Cen in the Milky Way where different generations of stars are enriched by different contributors, and among these by core-collapse SNe (Gratton et al 2004) or from observations of the most massive GCs in M31 where the run of α to Fe-peak elements is consistent with a primordial enrichment from stars with masses larger than 10 M (Meylan et al 2001).…”

Section: Strong Radiative Cooling and The Location Of The Threshold Linementioning

confidence: 99%

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

Tenorio-Tagle

Silich

Martínez-González

et al. 2013

ApJ

Self Cite

View full text Add to dashboard Cite

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.

show abstract

On the Heating Efficiency Derived From Observations of Young Super Star Clusters in M82

Cited by 18 publications

References 34 publications

Can Dust Injected by SNe Explain the NIR–MIR Excess in Young Massive Stellar Clusters?

Can Dust Injected by SNe Explain the NIR–MIR Excess in Young Massive Stellar Clusters?

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

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

Contact Info

Product

Resources

About