%0 Generic %1 cormier2017constraints %A Cormier, D. %A Bendo, G. J. %A Hony, S. %A Lebouteiller, V. %A Madden, S. C. %A Galliano, F. %A Glover, S. C. O. %A Klessen, R. S. %A Abel, N. P. %A Bigiel, F. %A Clark, P. C. %D 2017 %K co galaxies metal poor %R 10.1093/mnrasl/slx034 %T New ALMA constraints on the star-forming ISM at low metallicity: A 50 pc view of the blue compact dwarf galaxy SBS0335-052 %U http://arxiv.org/abs/1702.08467 %X Properties of the cold interstellar medium of low-metallicity galaxies are not well-known due to the faintness and extremely small scale on which emission is expected. We present deep ALMA band 6 (230GHz) observations of the nearby, low-metallicity (12 + log(O/H) = 7.25) blue compact dwarf galaxy SBS0335-052 at an unprecedented resolution of 0.2 arcsec (52 pc). The 12CO J=2-1 line is not detected and we report a 3-sigma upper limit of LCO(2-1) = 3.6x10^4 K km/s pc^2. Assuming that molecular gas is converted into stars with a given depletion time, ranging from 0.02 to 2 Gyr, we find lower limits on the CO-to-H2 conversion factor alpha_CO in the range 10^2-10^4 Msun pc^-2 (K km/s)^-1. The continuum emission is detected and resolved over the two main super star clusters. Re-analysis of the IR-radio spectral energy distribution suggests that the mm-fluxes are not only free-free emission but are most likely also associated with a cold dust component coincident with the position of the brightest cluster. With standard dust properties, we estimate its mass to be as large as 10^5 Msun. Both line and continuum results suggest the presence of a large cold gas reservoir unseen in CO even with ALMA.

@misc{cormier2017constraints, abstract = {Properties of the cold interstellar medium of low-metallicity galaxies are not well-known due to the faintness and extremely small scale on which emission is expected. We present deep ALMA band 6 (230GHz) observations of the nearby, low-metallicity (12 + log(O/H) = 7.25) blue compact dwarf galaxy SBS0335-052 at an unprecedented resolution of 0.2 arcsec (52 pc). The 12CO J=2-1 line is not detected and we report a 3-sigma upper limit of LCO(2-1) = 3.6x10^4 K km/s pc^2. Assuming that molecular gas is converted into stars with a given depletion time, ranging from 0.02 to 2 Gyr, we find lower limits on the CO-to-H2 conversion factor alpha_CO in the range 10^2-10^4 Msun pc^-2 (K km/s)^-1. The continuum emission is detected and resolved over the two main super star clusters. Re-analysis of the IR-radio spectral energy distribution suggests that the mm-fluxes are not only free-free emission but are most likely also associated with a cold dust component coincident with the position of the brightest cluster. With standard dust properties, we estimate its mass to be as large as 10^5 Msun. Both line and continuum results suggest the presence of a large cold gas reservoir unseen in CO even with ALMA.}, added-at = {2017-03-02T07:23:19.000+0100}, author = {Cormier, D. and Bendo, G. J. and Hony, S. and Lebouteiller, V. and Madden, S. C. and Galliano, F. and Glover, S. C. O. and Klessen, R. S. and Abel, N. P. and Bigiel, F. and Clark, P. C.}, biburl = {https://www.bibsonomy.org/bibtex/25e43d7354fbc8cd5f459a8946cf9e8b1/miki}, description = {[1702.08467] New ALMA constraints on the star-forming ISM at low metallicity: A 50 pc view of the blue compact dwarf galaxy SBS0335-052}, doi = {10.1093/mnrasl/slx034}, interhash = {7b098821fa1709ebda6460d4d6476bd3}, intrahash = {5e43d7354fbc8cd5f459a8946cf9e8b1}, keywords = {co galaxies metal poor}, note = {cite arxiv:1702.08467Comment: accepted for publication in MNRAS}, timestamp = {2017-03-02T07:23:19.000+0100}, title = {New ALMA constraints on the star-forming ISM at low metallicity: A 50 pc view of the blue compact dwarf galaxy SBS0335-052}, url = {http://arxiv.org/abs/1702.08467}, year = 2017 }