Research Topics of my interest
- Compact star clusters: are they progenitors of globular clusters?
For more than a century, it was thought that there exist only two types of clusters --- Open Clusters and Globular Clusters (GCs). The former are blue, relatively young (<1 Gyr) and found in the galactic disk, whereas the Globular Clusters are red, old (5-10 Gyr) and occupy the halo. However, the impecable spatial resolution of the Hubble Space Telescope (HST) has resulted in the discovery of a third class of stellar clusters, that are compact like the Globular Clusters, but are blue like the Open Clusters. These are the Compact star clusters or more popularly known as Super Star Clusters (SSCs). Starburst galaxies, such as M82 host hundreds of them. We are carrying out a study of these clusters in M82 and other nearby galaxies. The questions that we aim to address in these studies are:- What are the physical conditions required to form such clusters?
- What are the physical processes that can destroy them?
- What fraction of these SSCs will survive to become future GCs?
Publications:
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HST/ACS imaging of M82: A comparison of mass and size distribution
functions of the younger nuclear and older disk clusters
Y. D. Mayya, R. Romano, L. H. Rodriguez-Merino, A. Luna, L. Carrasco, D. Rosa-Gonzalez (2008) ApJ, 679, 404
- Are the compact star clusters of M82 evolving towards Globular Clusters? Astro-ph/0710.2145 (In PV II conference, 2007)
Thesis projects
- Martha Bello (Ph.D. student) "Study of association between SSCc and giant HII regions in nearby galaxies using HST images"
- Mayra Santiago (Master's student) "Search for the population of SSCs in M81 using HST images"
One of the very few resolved SSCs: R136 at the center of 30 Doradus in the LMC
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Ring galaxies: their origin and evolution
Have you heard of a road accident between two cars converting one of them into a more attractive car? Well, there is one type of cosmic collision where such a thing happens --- a head-on collision between a spiral galaxy and a compact elliptical or a spheroidal galaxy, results in a galaxy with a beautyful ring, known as a ring galaxy. A crude analogy is the formation of an expanding circular wave (or ring) in a pond when a stone is dropped into it. Unlike a pond, where the matter (i.e. water) is completely in fluid form, a spiral galaxy contains much more matter that moves as rigid particles (i.e. stars) as compared to a fluid (i.e. gas). The intruder, an elliptical galaxy, shares some similarities with a stone, in the sense that it lacks fluid particles. Nevertheless, the bond between the stars (gravitational) is not as strong as the bond between the stone particles (molecular). In addition, there are second order effects, such as the compression caused of the expanding waves producing a flash of light in form of star formation. All these differences ensure that a ring galaxy is not just an astronomically giant pond wave, and instead is much more interesting to observe and study. The study of ring galaxies basically involves interpreting their presently observed structure in the frame work of the head-on collisional model. The most attractive and famous of the ring galaxies, the Cartwheel, quite well fits the basic scenario. Nevertheless, there are details that needs further study. In particular, our study is focussed addressing the following questions:- Are the photometric properties (colors, brightness etc.) consistent with the time elapsed since the collision in individual systems?
- How long it will take a ring galaxy to fade out?
- How it will look like in the future?
Publications:
- R. Romano, Y.D. Mayya and E. I. Vorobyov "Stellar disks of Collisional Ring Galaxies I. Deep multiband images, Radial intensity and color profiles, and confrontation with N-body simulations" Submitted to AJ (June 2007)
- The detection of non-thermal radio continuum spokes and the study of star formation in the Cartwheel
Mayya, Y. D. , Bizyaev, D., Romano, R., Garcia-Barreto, J.A., and Vorobyov, E.I.
ApJ, 620, L35 (2005) | Astroph/0501311 | Web Release- Optical Color Gradients in Star-Forming Ring Galaxies
Korchagin, V.I., Mayya, Y.D., & Vorobyov, E.I. ApJ, 554, 281-290 2001 June 10 astro-ph/0102385
- Chemical Abundance Gradients in the Star-forming Ring Galaxies
Korchagin, V.I., Vorobyov, E.I. & Mayya, Y.D., ApJ, 522, 767-771, 1999 September 10
- Surface brightness gradients produced by ring waves of star formation
Korchagin, V.I., Mayya, Y.D., Vorobyov, E.I. & Kembhavi, A.K. 1998, ApJ, 495, 757 | astro-ph/9711041
Thesis projects
- Roberto Romano - Ph.D. from INAOE (2006) "An optical and near infrared band photometric study of ring galaxies and their comparison with theoretical predictions"
- Kenia Osorio (Master's student) "A study of metallic abundance and star formation history of ring galaxies Arp141 and Arp143"
HST image of the Cartwheel
- Galactic and extragalactic star forming regions: from star counts
to Population Synthesis Models
- Density Gradients and Internal Dust in the Orion Nebula
Binette, L.; González-Gómez, D. I., & Mayya, Y. D. 2002, Rev Mex de Astronomía y Astrofísica 38, 279 - Use of Red supergiant spectral features as age indicators in
starburst regions
Mayya, Y.D. 1997, ApJL, 482, L149 | HTML | astro-ph | postscript.gz - Embedded Clusters in Giant Extragalactic HII Regions:
III. Extinction and Star Formation
Mayya, Y.D., & Prabhu, T.P. 1996, AJ, 111, 1252; - Embedded Clusters in Giant Extragalactic HII Regions:
II. Evolutionary Population Synthesis Model
Mayya, Y.D. 1995, AJ, 109, 2503; ====> data tables - Embedded Clusters in Giant Extragalactic HII Regions:
I. BVRH_alpha Photometry
Mayya, Y.D. 1994, AJ, 108, 1276; ====> data tables
Thesis projects - Ricardo Retes - Master's from INAOE (2008) "Embedded Young stellar population in the Galactic Molecular cloud associated with the source IRAS 18236-1205"
Publications:
- Density Gradients and Internal Dust in the Orion Nebula
- Star formation histories and morphology of nearby galaxies
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The Star Formation History of the Disk of the
Starburst galaxy M82
Y. D. Mayya, A. Bressan, L. Carrasco, and L. Hernandez-Martinez
The Astrophysical Journal, 649, 172-180, 2006 | astro-ph/0605669 -
The Discovery of Spiral Arms in the Starburst Galaxy M82
Y. D. Mayya, L. Carrasco, A. Luna
ApJ, 628:L33-L36, 2005 July 20 | astro-ph/0506275 | Web Release -
Star Formation History and Extinction in the central kpc of M82-like Starbursts
Mayya, Y. D. , Bressan, A., Rodriguez, M., Valdes, J.R., and Chavez, M. 2004, ApJ, 600, 188 - Near infrared and Optical morhology of the dusty galaxy NGC972
Mayya, Y. D., Ravindranath S. and Carrasco, L. 1998, AJ, 116, 1671 | astro-ph/9808008 | postscript.gz - Spatial Distribution of Far infrared emission in Spiral galaxies: I. Relation with Radio continuum emission
Publications:
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The Star Formation History of the Disk of the
Starburst galaxy M82