Search

Your search keyword '"Kennicutt R. C."' showing total 10 results
Start Over Author "Kennicutt R. C." Publisher institute of physics publishing
10 results on '"Kennicutt R. C."'

1. Extinction Maps and Dust-to-gas Ratios in Nearby Galaxies with LEGUS

Author

Kahre, L, Walterbos, R, Kim, H, Thilker, D, Calzetti, D, Lee, J, Sabbi, E, Ubeda, L, Aloisi, A, Cignoni, M, Cook, D, Dale, D, Elmegreen, B, Elmegreen, D, Fumagalli, M, Gallagher, J, Gouliermis, D, Grasha, K, Grebel, E, Hunter, D, Sacchi, E, Smith, L, Tosi, M, Adamo, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, De Mink, S, Dobbs, C, Evans, A, Herrero, A, Johnson, K, Kennicutt, R, Krumholz, M, Messa, M, Nair, P, Nota, A, Pellerin, A, Ryon, J, Schaerer, D, Shabani, F, Van Dyk, S, Whitmore, B, Wofford, A, Kahre L., Walterbos R. A., Kim H., Thilker D., Calzetti D., Lee J. C., Sabbi E., Ubeda L., Aloisi A., Cignoni M., Cook D. O., Dale D. A., Elmegreen B. G., Elmegreen D. M., Fumagalli M., Gallagher J. S., Gouliermis D. A., Grasha K., Grebel E. K., Hunter D. A., Sacchi E., Smith L. J., Tosi M., Adamo A., Andrews J. E., Ashworth G., Bright S. N., Brown T. M., Chandar R., Christian C., De Mink S. E., Dobbs C., Evans A. S., Herrero A., Johnson K. E., Kennicutt R. C., Krumholz M. R., Messa M., Nair P., Nota A., Pellerin A., Ryon J. E., Schaerer D., Shabani F., Van Dyk S. D., Whitmore B. C., Wofford A., Kahre, L, Walterbos, R, Kim, H, Thilker, D, Calzetti, D, Lee, J, Sabbi, E, Ubeda, L, Aloisi, A, Cignoni, M, Cook, D, Dale, D, Elmegreen, B, Elmegreen, D, Fumagalli, M, Gallagher, J, Gouliermis, D, Grasha, K, Grebel, E, Hunter, D, Sacchi, E, Smith, L, Tosi, M, Adamo, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, De Mink, S, Dobbs, C, Evans, A, Herrero, A, Johnson, K, Kennicutt, R, Krumholz, M, Messa, M, Nair, P, Nota, A, Pellerin, A, Ryon, J, Schaerer, D, Shabani, F, Van Dyk, S, Whitmore, B, Wofford, A, Kahre L., Walterbos R. A., Kim H., Thilker D., Calzetti D., Lee J. C., Sabbi E., Ubeda L., Aloisi A., Cignoni M., Cook D. O., Dale D. A., Elmegreen B. G., Elmegreen D. M., Fumagalli M., Gallagher J. S., Gouliermis D. A., Grasha K., Grebel E. K., Hunter D. A., Sacchi E., Smith L. J., Tosi M., Adamo A., Andrews J. E., Ashworth G., Bright S. N., Brown T. M., Chandar R., Christian C., De Mink S. E., Dobbs C., Evans A. S., Herrero A., Johnson K. E., Kennicutt R. C., Krumholz M. R., Messa M., Nair P., Nota A., Pellerin A., Ryon J. E., Schaerer D., Shabani F., Van Dyk S. D., Whitmore B. C., and Wofford A.

Abstract

We present a study of the dust-to-gas ratios in five nearby galaxies: NGC 628 (M74), NGC 6503, NGC 7793, UGC 5139 (Holmberg I), and UGC 4305 (Holmberg II). Using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from the Treasury program Legacy ExtraGalactic UV Survey (LEGUS) combined with archival HST/Advanced Camera for Surveys data, we correct thousands of individual stars for extinction across these five galaxies using an isochrone-matching (reddening-free Q) method. We generate extinction maps for each galaxy from the individual stellar extinctions using both adaptive and fixed resolution techniques and correlate these maps with neutral H i and CO gas maps from the literature, including the H i Nearby Galaxy Survey and the HERA CO-Line Extragalactic Survey. We calculate dust-to-gas ratios and investigate variations in the dust-to-gas ratio with galaxy metallicity. We find a power-law relationship between dust-to-gas ratio and metallicity, consistent with other studies of dust-to-gas ratio compared to metallicity. We find a change in the relation when H2 is not included. This implies that underestimation of in low-metallicity dwarfs from a too-low CO-to-H2 conversion factor X CO could have produced too low a slope in the derived relationship between dust-to-gas ratio and metallicity. We also compare our extinctions to those derived from fitting the spectral energy distribution (SED) using the Bayesian Extinction and Stellar Tool for NGC 7793 and find systematically lower extinctions from SED fitting as compared to isochrone matching.

Published
2018

2. The Resolved Stellar Populations in the LEGUS Galaxies1

Author

Sabbi, E, Calzetti, D, Ubeda, L, Adamo, A, Cignoni, M, Thilker, D, Aloisi, A, Elmegreen, B, Elmegreen, D, Gouliermis, D, Grebel, E, Messa, M, Smith, L, Tosi, M, Dolphin, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, Clayton, G, Cook, D, Dale, D, De Mink, S, Dobbs, C, Evans, A, Fumagalli, M, Gallagher, J, Grasha, K, Herrero, A, Hunter, D, Johnson, K, Kahre, L, Kennicutt, R, Kim, H, Krumholz, M, Lee, J, Lennon, D, Martin, C, Nair, P, Nota, A, Ostlin, G, Pellerin, A, Prieto, J, Regan, M, Ryon, J, Sacchi, E, Schaerer, D, Schiminovich, D, Shabani, F, Van Dyk, S, Walterbos, R, Whitmore, B, Wofford, A, Sabbi E., Calzetti D., Ubeda L., Adamo A., Cignoni M., Thilker D., Aloisi A., Elmegreen B. G., Elmegreen D. M., Gouliermis D. A., Grebel E. K., Messa M., Smith L. J., Tosi M., Dolphin A., Andrews J. E., Ashworth G., Bright S. N., Brown T. M., Chandar R., Christian C., Clayton G. C., Cook D. O., Dale D. A., De Mink S. E., Dobbs C., Evans A. S., Fumagalli M., Gallagher J. S., Grasha K., Herrero A., Hunter D. A., Johnson K. E., Kahre L., Kennicutt R. C., Kim H., Krumholz M. R., Lee J. C., Lennon D., Martin C., Nair P., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M. W., Ryon J. E., Sacchi E., Schaerer D., Schiminovich D., Shabani F., Van Dyk S. D., Walterbos R., Whitmore B. C., Wofford A., Sabbi, E, Calzetti, D, Ubeda, L, Adamo, A, Cignoni, M, Thilker, D, Aloisi, A, Elmegreen, B, Elmegreen, D, Gouliermis, D, Grebel, E, Messa, M, Smith, L, Tosi, M, Dolphin, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, Clayton, G, Cook, D, Dale, D, De Mink, S, Dobbs, C, Evans, A, Fumagalli, M, Gallagher, J, Grasha, K, Herrero, A, Hunter, D, Johnson, K, Kahre, L, Kennicutt, R, Kim, H, Krumholz, M, Lee, J, Lennon, D, Martin, C, Nair, P, Nota, A, Ostlin, G, Pellerin, A, Prieto, J, Regan, M, Ryon, J, Sacchi, E, Schaerer, D, Schiminovich, D, Shabani, F, Van Dyk, S, Walterbos, R, Whitmore, B, Wofford, A, Sabbi E., Calzetti D., Ubeda L., Adamo A., Cignoni M., Thilker D., Aloisi A., Elmegreen B. G., Elmegreen D. M., Gouliermis D. A., Grebel E. K., Messa M., Smith L. J., Tosi M., Dolphin A., Andrews J. E., Ashworth G., Bright S. N., Brown T. M., Chandar R., Christian C., Clayton G. C., Cook D. O., Dale D. A., De Mink S. E., Dobbs C., Evans A. S., Fumagalli M., Gallagher J. S., Grasha K., Herrero A., Hunter D. A., Johnson K. E., Kahre L., Kennicutt R. C., Kim H., Krumholz M. R., Lee J. C., Lennon D., Martin C., Nair P., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M. W., Ryon J. E., Sacchi E., Schaerer D., Schiminovich D., Shabani F., Van Dyk S. D., Walterbos R., Whitmore B. C., and Wofford A.

Abstract

The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle 21 Treasury program on the Hubble Space Telescope. It studied 50 nearby star-forming galaxies in 5 bands from the near-UV to the I-band, combining new Wide Field Camera 3 observations with archival Advanced Camera for Surveys data. LEGUS was designed to investigate how star formation occurs and develops on both small and large scales, and how it relates to the galactic environments. In this paper we present the photometric catalogs for all the apparently single stars identified in the 50 LEGUS galaxies. Photometric catalogs and mosaicked images for all filters are available for download. We present optical and near-UV color-magnitude diagrams for all the galaxies. For each galaxy we derived the distance from the tip of the red giant branch. We then used the NUV color-magnitude diagrams to identify stars more massive than 14 M o, and compared their number with the number of massive stars expected from the GALEX FUV luminosity. Our analysis shows that the fraction of massive stars forming in star clusters and stellar associations is about constant with the star formation rate. This lack of a relation suggests that the timescale for evaporation of unbound structures is comparable or longer than 10 Myr. At low star formation rates this translates to an excess of mass in clustered environments as compared to model predictions of cluster evolution, suggesting that a significant fraction of stars form in unbound systems

Published
2018

3. A Study of Two Dwarf Irregular Galaxies with Asymmetrical Star Formation Distributions

Author

Hunter, D, Gallardo, S, Zhang, H, Adamo, A, Cook, D, Oh, S, Elmegreen, B, Kim, H, Kahre, L, Ubeda, L, Bright, S, Ryon, J, Fumagalli, M, Sacchi, E, Kennicutt, R, Tosi, M, Dale, D, Cignoni, M, Messa, M, Grebel, E, Gouliermis, D, Sabbi, E, Grasha, K, Gallagher, J, Calzetti, D, Lee, J, Hunter D. A., Gallardo S., Zhang H. -X., Adamo A., Cook D. O., Oh S. -H., Elmegreen B. G., Kim H., Kahre L., Ubeda L., Bright S. N., Ryon J. E., Fumagalli M., Sacchi E., Kennicutt R. C., Tosi M., Dale D. A., Cignoni M., Messa M., Grebel E. K., Gouliermis D. A., Sabbi E., Grasha K., Gallagher J. S., Calzetti D., Lee J. C., Hunter, D, Gallardo, S, Zhang, H, Adamo, A, Cook, D, Oh, S, Elmegreen, B, Kim, H, Kahre, L, Ubeda, L, Bright, S, Ryon, J, Fumagalli, M, Sacchi, E, Kennicutt, R, Tosi, M, Dale, D, Cignoni, M, Messa, M, Grebel, E, Gouliermis, D, Sabbi, E, Grasha, K, Gallagher, J, Calzetti, D, Lee, J, Hunter D. A., Gallardo S., Zhang H. -X., Adamo A., Cook D. O., Oh S. -H., Elmegreen B. G., Kim H., Kahre L., Ubeda L., Bright S. N., Ryon J. E., Fumagalli M., Sacchi E., Kennicutt R. C., Tosi M., Dale D. A., Cignoni M., Messa M., Grebel E. K., Gouliermis D. A., Sabbi E., Grasha K., Gallagher J. S., Calzetti D., and Lee J. C.

Abstract

Two dwarf irregular galaxies, DDO 187 and NGC 3738, exhibit a striking pattern of star formation: intense star formation is taking place in a large region occupying roughly half of the inner part of the optical galaxy. We use data on the H i distribution and kinematics and stellar images and colors to examine the properties of the environment in the high star formation rate (HSF) halves of the galaxies in comparison with the low star formation rate halves. We find that the pressure and gas density are higher on the HSF sides by 30%-70%. In addition we find in both galaxies that the H i velocity fields exhibit significant deviations from ordered rotation and there are large regions of high-velocity dispersion and multiple velocity components in the gas beyond the inner regions of the galaxies. The conditions in the HSF regions are likely the result of large-scale external processes affecting the internal environment of the galaxies and enabling the current star formation there.

Published
2018

4. The Resolved Stellar Populations in the LEGUS Galaxies1

Author

Sabbi, E, Calzetti, D, Ubeda, L, Adamo, A, Cignoni, M, Thilker, D, Aloisi, A, Elmegreen, B, Elmegreen, D, Gouliermis, D, Grebel, E, Messa, M, Smith, L, Tosi, M, Dolphin, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, Clayton, G, Cook, D, Dale, D, De Mink, S, Dobbs, C, Evans, A, Fumagalli, M, Gallagher, J, Grasha, K, Herrero, A, Hunter, D, Johnson, K, Kahre, L, Kennicutt, R, Kim, H, Krumholz, M, Lee, J, Lennon, D, Martin, C, Nair, P, Nota, A, Ostlin, G, Pellerin, A, Prieto, J, Regan, M, Ryon, J, Sacchi, E, Schaerer, D, Schiminovich, D, Shabani, F, Van Dyk, S, Walterbos, R, Whitmore, B, Wofford, A, Sabbi E., Calzetti D., Ubeda L., Adamo A., Cignoni M., Thilker D., Aloisi A., Elmegreen B. G., Elmegreen D. M., Gouliermis D. A., Grebel E. K., Messa M., Smith L. J., Tosi M., Dolphin A., Andrews J. E., Ashworth G., Bright S. N., Brown T. M., Chandar R., Christian C., Clayton G. C., Cook D. O., Dale D. A., De Mink S. E., Dobbs C., Evans A. S., Fumagalli M., Gallagher J. S., Grasha K., Herrero A., Hunter D. A., Johnson K. E., Kahre L., Kennicutt R. C., Kim H., Krumholz M. R., Lee J. C., Lennon D., Martin C., Nair P., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M. W., Ryon J. E., Sacchi E., Schaerer D., Schiminovich D., Shabani F., Van Dyk S. D., Walterbos R., Whitmore B. C., Wofford A., Sabbi, E, Calzetti, D, Ubeda, L, Adamo, A, Cignoni, M, Thilker, D, Aloisi, A, Elmegreen, B, Elmegreen, D, Gouliermis, D, Grebel, E, Messa, M, Smith, L, Tosi, M, Dolphin, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, Clayton, G, Cook, D, Dale, D, De Mink, S, Dobbs, C, Evans, A, Fumagalli, M, Gallagher, J, Grasha, K, Herrero, A, Hunter, D, Johnson, K, Kahre, L, Kennicutt, R, Kim, H, Krumholz, M, Lee, J, Lennon, D, Martin, C, Nair, P, Nota, A, Ostlin, G, Pellerin, A, Prieto, J, Regan, M, Ryon, J, Sacchi, E, Schaerer, D, Schiminovich, D, Shabani, F, Van Dyk, S, Walterbos, R, Whitmore, B, Wofford, A, Sabbi E., Calzetti D., Ubeda L., Adamo A., Cignoni M., Thilker D., Aloisi A., Elmegreen B. G., Elmegreen D. M., Gouliermis D. A., Grebel E. K., Messa M., Smith L. J., Tosi M., Dolphin A., Andrews J. E., Ashworth G., Bright S. N., Brown T. M., Chandar R., Christian C., Clayton G. C., Cook D. O., Dale D. A., De Mink S. E., Dobbs C., Evans A. S., Fumagalli M., Gallagher J. S., Grasha K., Herrero A., Hunter D. A., Johnson K. E., Kahre L., Kennicutt R. C., Kim H., Krumholz M. R., Lee J. C., Lennon D., Martin C., Nair P., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M. W., Ryon J. E., Sacchi E., Schaerer D., Schiminovich D., Shabani F., Van Dyk S. D., Walterbos R., Whitmore B. C., and Wofford A.

Abstract

The Legacy ExtraGalactic UV Survey (LEGUS) is a multiwavelength Cycle 21 Treasury program on the Hubble Space Telescope. It studied 50 nearby star-forming galaxies in 5 bands from the near-UV to the I-band, combining new Wide Field Camera 3 observations with archival Advanced Camera for Surveys data. LEGUS was designed to investigate how star formation occurs and develops on both small and large scales, and how it relates to the galactic environments. In this paper we present the photometric catalogs for all the apparently single stars identified in the 50 LEGUS galaxies. Photometric catalogs and mosaicked images for all filters are available for download. We present optical and near-UV color-magnitude diagrams for all the galaxies. For each galaxy we derived the distance from the tip of the red giant branch. We then used the NUV color-magnitude diagrams to identify stars more massive than 14 M o, and compared their number with the number of massive stars expected from the GALEX FUV luminosity. Our analysis shows that the fraction of massive stars forming in star clusters and stellar associations is about constant with the star formation rate. This lack of a relation suggests that the timescale for evaporation of unbound structures is comparable or longer than 10 Myr. At low star formation rates this translates to an excess of mass in clustered environments as compared to model predictions of cluster evolution, suggesting that a significant fraction of stars form in unbound systems

Published
2018

5. Extinction Maps and Dust-to-gas Ratios in Nearby Galaxies with LEGUS

Author

Kahre, L, Walterbos, R, Kim, H, Thilker, D, Calzetti, D, Lee, J, Sabbi, E, Ubeda, L, Aloisi, A, Cignoni, M, Cook, D, Dale, D, Elmegreen, B, Elmegreen, D, Fumagalli, M, Gallagher, J, Gouliermis, D, Grasha, K, Grebel, E, Hunter, D, Sacchi, E, Smith, L, Tosi, M, Adamo, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, De Mink, S, Dobbs, C, Evans, A, Herrero, A, Johnson, K, Kennicutt, R, Krumholz, M, Messa, M, Nair, P, Nota, A, Pellerin, A, Ryon, J, Schaerer, D, Shabani, F, Van Dyk, S, Whitmore, B, Wofford, A, Kahre L., Walterbos R. A., Kim H., Thilker D., Calzetti D., Lee J. C., Sabbi E., Ubeda L., Aloisi A., Cignoni M., Cook D. O., Dale D. A., Elmegreen B. G., Elmegreen D. M., Fumagalli M., Gallagher J. S., Gouliermis D. A., Grasha K., Grebel E. K., Hunter D. A., Sacchi E., Smith L. J., Tosi M., Adamo A., Andrews J. E., Ashworth G., Bright S. N., Brown T. M., Chandar R., Christian C., De Mink S. E., Dobbs C., Evans A. S., Herrero A., Johnson K. E., Kennicutt R. C., Krumholz M. R., Messa M., Nair P., Nota A., Pellerin A., Ryon J. E., Schaerer D., Shabani F., Van Dyk S. D., Whitmore B. C., Wofford A., Kahre, L, Walterbos, R, Kim, H, Thilker, D, Calzetti, D, Lee, J, Sabbi, E, Ubeda, L, Aloisi, A, Cignoni, M, Cook, D, Dale, D, Elmegreen, B, Elmegreen, D, Fumagalli, M, Gallagher, J, Gouliermis, D, Grasha, K, Grebel, E, Hunter, D, Sacchi, E, Smith, L, Tosi, M, Adamo, A, Andrews, J, Ashworth, G, Bright, S, Brown, T, Chandar, R, Christian, C, De Mink, S, Dobbs, C, Evans, A, Herrero, A, Johnson, K, Kennicutt, R, Krumholz, M, Messa, M, Nair, P, Nota, A, Pellerin, A, Ryon, J, Schaerer, D, Shabani, F, Van Dyk, S, Whitmore, B, Wofford, A, Kahre L., Walterbos R. A., Kim H., Thilker D., Calzetti D., Lee J. C., Sabbi E., Ubeda L., Aloisi A., Cignoni M., Cook D. O., Dale D. A., Elmegreen B. G., Elmegreen D. M., Fumagalli M., Gallagher J. S., Gouliermis D. A., Grasha K., Grebel E. K., Hunter D. A., Sacchi E., Smith L. J., Tosi M., Adamo A., Andrews J. E., Ashworth G., Bright S. N., Brown T. M., Chandar R., Christian C., De Mink S. E., Dobbs C., Evans A. S., Herrero A., Johnson K. E., Kennicutt R. C., Krumholz M. R., Messa M., Nair P., Nota A., Pellerin A., Ryon J. E., Schaerer D., Shabani F., Van Dyk S. D., Whitmore B. C., and Wofford A.

Abstract

We present a study of the dust-to-gas ratios in five nearby galaxies: NGC 628 (M74), NGC 6503, NGC 7793, UGC 5139 (Holmberg I), and UGC 4305 (Holmberg II). Using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from the Treasury program Legacy ExtraGalactic UV Survey (LEGUS) combined with archival HST/Advanced Camera for Surveys data, we correct thousands of individual stars for extinction across these five galaxies using an isochrone-matching (reddening-free Q) method. We generate extinction maps for each galaxy from the individual stellar extinctions using both adaptive and fixed resolution techniques and correlate these maps with neutral H i and CO gas maps from the literature, including the H i Nearby Galaxy Survey and the HERA CO-Line Extragalactic Survey. We calculate dust-to-gas ratios and investigate variations in the dust-to-gas ratio with galaxy metallicity. We find a power-law relationship between dust-to-gas ratio and metallicity, consistent with other studies of dust-to-gas ratio compared to metallicity. We find a change in the relation when H2 is not included. This implies that underestimation of in low-metallicity dwarfs from a too-low CO-to-H2 conversion factor X CO could have produced too low a slope in the derived relationship between dust-to-gas ratio and metallicity. We also compare our extinctions to those derived from fitting the spectral energy distribution (SED) using the Bayesian Extinction and Stellar Tool for NGC 7793 and find systematically lower extinctions from SED fitting as compared to isochrone matching.

Published
2018

6. Legacy ExtraGalactic UV Survey with the Hubble Space Telescope: Stellar Cluster Catalogs and First Insights into Cluster Formation and Evolution in NGC 628

Author

Adamo, A, Ryon, J, Messa, M, Kim, H, Grasha, K, Cook, D, Calzetti, D, Lee, J, Whitmore, B, Elmegreen, B, Ubeda, L, Smith, L, Bright, S, Runnholm, A, Andrews, J, Fumagalli, M, Gouliermis, D, Kahre, L, Nair, P, Thilker, D, Walterbos, R, Wofford, A, Aloisi, A, Ashworth, G, Brown, T, Chandar, R, Christian, C, Cignoni, M, Clayton, G, Dale, D, De Mink, S, Dobbs, C, Elmegreen, D, Evans, A, Gallagher, J, Grebel, E, Herrero, A, Hunter, D, Johnson, K, Kennicutt, R, Krumholz, M, Lennon, D, Levay, K, Martin, C, Nota, A, Ostlin, G, Pellerin, A, Prieto, J, Regan, M, Sabbi, E, Sacchi, E, Schaerer, D, Schiminovich, D, Shabani, F, Tosi, M, Van Dyk, S, Zackrisson, E, Adamo A., Ryon J. E., Messa M., Kim H., Grasha K., Cook D. O., Calzetti D., Lee J. C., Whitmore B. C., Elmegreen B. G., Ubeda L., Smith L. J., Bright S. N., Runnholm A., Andrews J. E., Fumagalli M., Gouliermis D. A., Kahre L., Nair P., Thilker D., Walterbos R., Wofford A., Aloisi A., Ashworth G., Brown T. M., Chandar R., Christian C., Cignoni M., Clayton G. C., Dale D. A., De Mink S. E., Dobbs C., Elmegreen D. M., Evans A. S., Gallagher J. S., Grebel E. K., Herrero A., Hunter D. A., Johnson K. E., Kennicutt R. C., Krumholz M. R., Lennon D., Levay K., Martin C., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M. W., Sabbi E., Sacchi E., Schaerer D., Schiminovich D., Shabani F., Tosi M., Van Dyk S. D., Zackrisson E., Adamo, A, Ryon, J, Messa, M, Kim, H, Grasha, K, Cook, D, Calzetti, D, Lee, J, Whitmore, B, Elmegreen, B, Ubeda, L, Smith, L, Bright, S, Runnholm, A, Andrews, J, Fumagalli, M, Gouliermis, D, Kahre, L, Nair, P, Thilker, D, Walterbos, R, Wofford, A, Aloisi, A, Ashworth, G, Brown, T, Chandar, R, Christian, C, Cignoni, M, Clayton, G, Dale, D, De Mink, S, Dobbs, C, Elmegreen, D, Evans, A, Gallagher, J, Grebel, E, Herrero, A, Hunter, D, Johnson, K, Kennicutt, R, Krumholz, M, Lennon, D, Levay, K, Martin, C, Nota, A, Ostlin, G, Pellerin, A, Prieto, J, Regan, M, Sabbi, E, Sacchi, E, Schaerer, D, Schiminovich, D, Shabani, F, Tosi, M, Van Dyk, S, Zackrisson, E, Adamo A., Ryon J. E., Messa M., Kim H., Grasha K., Cook D. O., Calzetti D., Lee J. C., Whitmore B. C., Elmegreen B. G., Ubeda L., Smith L. J., Bright S. N., Runnholm A., Andrews J. E., Fumagalli M., Gouliermis D. A., Kahre L., Nair P., Thilker D., Walterbos R., Wofford A., Aloisi A., Ashworth G., Brown T. M., Chandar R., Christian C., Cignoni M., Clayton G. C., Dale D. A., De Mink S. E., Dobbs C., Elmegreen D. M., Evans A. S., Gallagher J. S., Grebel E. K., Herrero A., Hunter D. A., Johnson K. E., Kennicutt R. C., Krumholz M. R., Lennon D., Levay K., Martin C., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M. W., Sabbi E., Sacchi E., Schaerer D., Schiminovich D., Shabani F., Tosi M., Van Dyk S. D., and Zackrisson E.

Abstract

We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes and a truncation of a few times 105. After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find mass-independent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (≤104) clusters, suggesting that a mass-dependent component is necessary to fully describe the YSC disruption process in NGC 628.

Published
2017

7. The Hierarchical Distribution of the Young Stellar Clusters in Six Local Star-forming Galaxies

Author

Grasha, K, Calzetti, D, Adamo, A, Kim, H, Elmegreen, B, Gouliermis, D, Dale, D, Fumagalli, M, Grebel, E, Johnson, K, Kahre, L, Kennicutt, R, Messa, M, Pellerin, A, Ryon, J, Smith, L, Shabani, F, Thilker, D, Ubeda, L, Grasha K., Calzetti D., Adamo A., Kim H., Elmegreen B. G., Gouliermis D. A., Dale D. A., Fumagalli M., Grebel E. K., Johnson K. E., Kahre L., Kennicutt R. C., Messa M., Pellerin A., Ryon J. E., Smith L. J., Shabani F., Thilker D., Ubeda L., Grasha, K, Calzetti, D, Adamo, A, Kim, H, Elmegreen, B, Gouliermis, D, Dale, D, Fumagalli, M, Grebel, E, Johnson, K, Kahre, L, Kennicutt, R, Messa, M, Pellerin, A, Ryon, J, Smith, L, Shabani, F, Thilker, D, Ubeda, L, Grasha K., Calzetti D., Adamo A., Kim H., Elmegreen B. G., Gouliermis D. A., Dale D. A., Fumagalli M., Grebel E. K., Johnson K. E., Kahre L., Kennicutt R. C., Messa M., Pellerin A., Ryon J. E., Smith L. J., Shabani F., Thilker D., and Ubeda L.

Abstract

We present a study of the hierarchical clustering of the young stellar clusters in six local (3-15 Mpc) star-forming galaxies using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from the Treasury Program LEGUS (Legacy ExtraGalactic UV Survey). We identified 3685 likely clusters and associations, each visually classified by their morphology, and we use the angular two-point correlation function to study the clustering of these stellar systems. We find that the spatial distribution of the young clusters and associations are clustered with respect to each other, forming large, unbound hierarchical star-forming complexes that are in general very young. The strength of the clustering decreases with increasing age of the star clusters and stellar associations, becoming more homogeneously distributed after ∼40-60 Myr and on scales larger than a few hundred parsecs. In all galaxies, the associations exhibit a global behavior that is distinct and more strongly correlated from compact clusters. Thus, populations of clusters are more evolved than associations in terms of their spatial distribution, traveling significantly from their birth site within a few tens of Myr, whereas associations show evidence of disruption occurring very quickly after their formation. The clustering of the stellar systems resembles that of a turbulent interstellar medium that drives the star formation process, correlating the components in unbound star-forming complexes in a hierarchical manner, dispersing shortly after formation, suggestive of a single, continuous mode of star formation across all galaxies

Published
2017

8. The Hierarchical Distribution of the Young Stellar Clusters in Six Local Star-forming Galaxies

Author

Grasha, K, Calzetti, D, Adamo, A, Kim, H, Elmegreen, B, Gouliermis, D, Dale, D, Fumagalli, M, Grebel, E, Johnson, K, Kahre, L, Kennicutt, R, Messa, M, Pellerin, A, Ryon, J, Smith, L, Shabani, F, Thilker, D, Ubeda, L, Grasha K., Calzetti D., Adamo A., Kim H., Elmegreen B. G., Gouliermis D. A., Dale D. A., Fumagalli M., Grebel E. K., Johnson K. E., Kahre L., Kennicutt R. C., Messa M., Pellerin A., Ryon J. E., Smith L. J., Shabani F., Thilker D., Ubeda L., Grasha, K, Calzetti, D, Adamo, A, Kim, H, Elmegreen, B, Gouliermis, D, Dale, D, Fumagalli, M, Grebel, E, Johnson, K, Kahre, L, Kennicutt, R, Messa, M, Pellerin, A, Ryon, J, Smith, L, Shabani, F, Thilker, D, Ubeda, L, Grasha K., Calzetti D., Adamo A., Kim H., Elmegreen B. G., Gouliermis D. A., Dale D. A., Fumagalli M., Grebel E. K., Johnson K. E., Kahre L., Kennicutt R. C., Messa M., Pellerin A., Ryon J. E., Smith L. J., Shabani F., Thilker D., and Ubeda L.

Abstract

We present a study of the hierarchical clustering of the young stellar clusters in six local (3-15 Mpc) star-forming galaxies using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from the Treasury Program LEGUS (Legacy ExtraGalactic UV Survey). We identified 3685 likely clusters and associations, each visually classified by their morphology, and we use the angular two-point correlation function to study the clustering of these stellar systems. We find that the spatial distribution of the young clusters and associations are clustered with respect to each other, forming large, unbound hierarchical star-forming complexes that are in general very young. The strength of the clustering decreases with increasing age of the star clusters and stellar associations, becoming more homogeneously distributed after ∼40-60 Myr and on scales larger than a few hundred parsecs. In all galaxies, the associations exhibit a global behavior that is distinct and more strongly correlated from compact clusters. Thus, populations of clusters are more evolved than associations in terms of their spatial distribution, traveling significantly from their birth site within a few tens of Myr, whereas associations show evidence of disruption occurring very quickly after their formation. The clustering of the stellar systems resembles that of a turbulent interstellar medium that drives the star formation process, correlating the components in unbound star-forming complexes in a hierarchical manner, dispersing shortly after formation, suggestive of a single, continuous mode of star formation across all galaxies

Published
2017

9. Legacy ExtraGalactic UV Survey with the Hubble Space Telescope: Stellar Cluster Catalogs and First Insights into Cluster Formation and Evolution in NGC 628

Author

Adamo, A, Ryon, J, Messa, M, Kim, H, Grasha, K, Cook, D, Calzetti, D, Lee, J, Whitmore, B, Elmegreen, B, Ubeda, L, Smith, L, Bright, S, Runnholm, A, Andrews, J, Fumagalli, M, Gouliermis, D, Kahre, L, Nair, P, Thilker, D, Walterbos, R, Wofford, A, Aloisi, A, Ashworth, G, Brown, T, Chandar, R, Christian, C, Cignoni, M, Clayton, G, Dale, D, De Mink, S, Dobbs, C, Elmegreen, D, Evans, A, Gallagher, J, Grebel, E, Herrero, A, Hunter, D, Johnson, K, Kennicutt, R, Krumholz, M, Lennon, D, Levay, K, Martin, C, Nota, A, Ostlin, G, Pellerin, A, Prieto, J, Regan, M, Sabbi, E, Sacchi, E, Schaerer, D, Schiminovich, D, Shabani, F, Tosi, M, Van Dyk, S, Zackrisson, E, Adamo A., Ryon J. E., Messa M., Kim H., Grasha K., Cook D. O., Calzetti D., Lee J. C., Whitmore B. C., Elmegreen B. G., Ubeda L., Smith L. J., Bright S. N., Runnholm A., Andrews J. E., Fumagalli M., Gouliermis D. A., Kahre L., Nair P., Thilker D., Walterbos R., Wofford A., Aloisi A., Ashworth G., Brown T. M., Chandar R., Christian C., Cignoni M., Clayton G. C., Dale D. A., De Mink S. E., Dobbs C., Elmegreen D. M., Evans A. S., Gallagher J. S., Grebel E. K., Herrero A., Hunter D. A., Johnson K. E., Kennicutt R. C., Krumholz M. R., Lennon D., Levay K., Martin C., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M. W., Sabbi E., Sacchi E., Schaerer D., Schiminovich D., Shabani F., Tosi M., Van Dyk S. D., Zackrisson E., Adamo, A, Ryon, J, Messa, M, Kim, H, Grasha, K, Cook, D, Calzetti, D, Lee, J, Whitmore, B, Elmegreen, B, Ubeda, L, Smith, L, Bright, S, Runnholm, A, Andrews, J, Fumagalli, M, Gouliermis, D, Kahre, L, Nair, P, Thilker, D, Walterbos, R, Wofford, A, Aloisi, A, Ashworth, G, Brown, T, Chandar, R, Christian, C, Cignoni, M, Clayton, G, Dale, D, De Mink, S, Dobbs, C, Elmegreen, D, Evans, A, Gallagher, J, Grebel, E, Herrero, A, Hunter, D, Johnson, K, Kennicutt, R, Krumholz, M, Lennon, D, Levay, K, Martin, C, Nota, A, Ostlin, G, Pellerin, A, Prieto, J, Regan, M, Sabbi, E, Sacchi, E, Schaerer, D, Schiminovich, D, Shabani, F, Tosi, M, Van Dyk, S, Zackrisson, E, Adamo A., Ryon J. E., Messa M., Kim H., Grasha K., Cook D. O., Calzetti D., Lee J. C., Whitmore B. C., Elmegreen B. G., Ubeda L., Smith L. J., Bright S. N., Runnholm A., Andrews J. E., Fumagalli M., Gouliermis D. A., Kahre L., Nair P., Thilker D., Walterbos R., Wofford A., Aloisi A., Ashworth G., Brown T. M., Chandar R., Christian C., Cignoni M., Clayton G. C., Dale D. A., De Mink S. E., Dobbs C., Elmegreen D. M., Evans A. S., Gallagher J. S., Grebel E. K., Herrero A., Hunter D. A., Johnson K. E., Kennicutt R. C., Krumholz M. R., Lennon D., Levay K., Martin C., Nota A., Ostlin G., Pellerin A., Prieto J., Regan M. W., Sabbi E., Sacchi E., Schaerer D., Schiminovich D., Shabani F., Tosi M., Van Dyk S. D., and Zackrisson E.

Abstract

We report the large effort that is producing comprehensive high-level young star cluster (YSC) catalogs for a significant fraction of galaxies observed with the Legacy ExtraGalactic UV Survey (LEGUS) Hubble treasury program. We present the methodology developed to extract cluster positions, verify their genuine nature, produce multiband photometry (from NUV to NIR), and derive their physical properties via spectral energy distribution fitting analyses. We use the nearby spiral galaxy NGC 628 as a test case for demonstrating the impact that LEGUS will have on our understanding of the formation and evolution of YSCs and compact stellar associations within their host galaxy. Our analysis of the cluster luminosity function from the UV to the NIR finds a steepening at the bright end and at all wavelengths suggesting a dearth of luminous clusters. The cluster mass function of NGC 628 is consistent with a power-law distribution of slopes and a truncation of a few times 105. After their formation, YSCs and compact associations follow different evolutionary paths. YSCs survive for a longer time frame, confirming their being potentially bound systems. Associations disappear on timescales comparable to hierarchically organized star-forming regions, suggesting that they are expanding systems. We find mass-independent cluster disruption in the inner region of NGC 628, while in the outer part of the galaxy there is little or no disruption. We observe faster disruption rates for low mass (≤104) clusters, suggesting that a mass-dependent component is necessary to fully describe the YSC disruption process in NGC 628.

Published
2017

Catalog

Books, media, physical & digital resources
See catalog results