I am the Mission Scientist for the Data Science Mission Office at the Space Telescope Science Institute. My scientific work focuses on galaxy evolution. I am interested in how environment affects galaxy evolution, particularly in groups and high-redshift proto-clusters. I get my thrills from gravitational lenses, spectra, databases and well-documented APIs.
I am currently the Mission Scientist for the Data Science Mission Office at the Space Telescope Science Institute. Previously, I was an associate research scientist at the Yale University Department of Astronomy, working with the 3D-HST survey, a postdoc at the Carnegie Observatories in Pasadena and a graduate student at University of Arizona. Highlights from my CV are listed below and the complete pdf version is available for download.
Galaxy evolution and star-formation as a function of environment
Formation and evolution of groups and clusters of galaxies
Gravitational lensing, environments of gravitational lenses
Data Science Mission Office, Space Telescope Science Institute, Baltimore, MD
I have contributed to >40 refereed publications. As part of 3D-HST, I have been closely involved in the wide range of research topics pursued by the team: the evolution of Milky Way progenitors, of the star forming sequence, of the structural properties of galaxies since z~2.5, the build up of disks, the discovery of the most distant galaxy-galaxy lens and the discovery of z~10 candidates, to name a few. Listed below are articles where I have had a significant contribution. For my full list of publications, please visit the ADS Library or download the PDF below.
Momcheva, I., van Dokkum, P., van der Wel, A., Brammer, G., MacKenty, J., Nelson, E., Leja, J., Muzzin, A., Franx, M., "A New Method for Wide-field Near-IR Imaging with the Hubble Space Telescope", 2017PASP..129a5004M
Momcheva, I., Brammer, Gabriel B., van Dokkum, Pieter G., Skelton, Rosalind E., Whitaker, Katherine E. et. al., "The 3D-HST Survey: Hubble Space Telescope WFC3/G141 grism spectra, redshifts, and emission line measurements for ~ 100,000 galaxies", 2016ApJS..225...27M
Momcheva, I. & Tollerud, Erik "Software Use in Astronomy: an Informal Survey", arXiv:1507.03989
Momcheva, I., Williams, K. A., Cool, R. J., Keeton, C. R., Zabludoff, A.I., "A Spectroscopic Survey of the Fields of 28 Strong Gravitational Lenses: The Redshift Catalog", accepted to ApJS, arXiv:1503.02074
Prescott, M. K. M., Momcheva, I., Brammer, G. B., Fynbo, J. P. U., Moller, P., "Overturning the Case for Gravitational Powering in the Prototypical Cooling Lyman-alpha Nebula", 2015, ArXiv e-prints , arXiv:1501.05312, accepted
Skelton, R. E., Whitaker, K. E., Momcheva, I., Brammer, G. B., van Dokkum, P. G., Labbe, I., Franx, M., van der Wel, A., Bezanson, R., Da Cunha, E., Fumagalli, M., Foerster Schreiber, N., Kriek, M., Leja, J., Lundgren, B. F., Magee, D., Marchesini, D., Maseda, M. V., Nelson, E. J., Oesch, P., Pacifici, C., Patel, S. G., Price, S., Rix, H.-W., Tal, T., Wake, D. A., Wuyts, S., "3D-HST WFC3-selected Photometric Catalogs in the Five CANDELS/3D-HST Fields: Photometry, Photometric Redshifts and Stellar Masses", 2014, ApJS, 214, 49
Wong, K. C., Tran, K.-V. H., Suyu, S. H., Momcheva, I., Brammer, G. B., Brodwin, M., Gonzalez, A. H., Halkola, A., Kacprzak, G. G., Koekemoer, A. M., Papovich, C. J., Rudnick, G. H., "Discovery of a Strong Lensing Galaxy Embedded in a Cluster at z = 1.62", 2014, ApJL, 789, L31
Leja, J., van Dokkum, P. G., Momcheva, I., Brammer, G., Skelton, R. E., Whitaker, K. E., Andrews, B. H., Franx, M., Kriek, M., van der Wel, A., Bezanson, R., Conroy, C., Forster Schreiber, N., Nelson, E., Patel, S. G., "Exploring the Chemical Link between Local Ellipticals and Their High-redshift Progenitors", 2013, ApJL, 778, L24
van Dokkum, P., Brammer, G., Momcheva, I., Skelton, R. E., Whitaker, K. E., for the 3D-HST team, "3D- HST Data Release v3.0: Extremely Deep Spectra in the UDF and WFC3 Mosaics in the 3D-HST/CANDELS Fields", 2013, ArXiv e-prints, arXiv:1305.2140
Momcheva, I., Lee, J. C., Ly, C., Salim, S., Dale, D. A., Ouchi, M., Finn, R., Ono, Y., "Nebular Attenuation in Hα-selected Star-forming Galaxies at z = 0.8 from the NewHα Survey", 2013, AJ, 145, 47
Nelson, E. J., van Dokkum, P. G., Momcheva, I., Brammer, G., Lundgren, B., Skelton, R. E., Whitaker, K. E., Da Cunha, E., Forster Schreiber, N., Franx, M., Fumagalli, M., Kriek, M., Labbe, I., Leja, J., Patel, S., Rix, H.-W., Schmidt, K. B., van der Wel, A., Wuyts, S., "The Radial Distribution of Star Formation in Galaxies at z ∼ 1 from the 3D-HST Survey", 2013, ApJL, 763, L16
Papovich, C., Momcheva, I., Willmer, C. N. A. et al., "A Spitzer-selected Galaxy Cluster at z = 1.62" , 2010, ApJ, 716, 1503
Momcheva, I., Williams, K. A., Keeton, C. R., Zabludoff, A.I., "A Spectroscopic Study of the Environ- ments of Gravitational Lens Galaxies" , 2006, ApJ, 641, 169
Williams, K. A., Momcheva, I. G., Keeton, C. R., Zabludoff, A.I., Lehar, J., "First Results from a Photometric Survey of Strong Gravitational Lens Environments", 2006, ApJ, 646, 85
Click on the images below for more information on the projects I am involved in.
Galaxy clusters are the most massive gravitationally-bound structures in the Universe. The redshift evolution of the number densities of clusters, especially at z>1, provides strong constraints on the cosmic matter density and the equation of state. Furthermore, clusters are ideal laboratories for the studies of hierarchal galaxy formation and the build up of the red sequence. However, very few clusters have been spectroscopically confirmed at z~1.5. A new, unbiased method to discover such clusters is to identify them as over-densities of galaxies with red [3.6um]-[4.5um] Spitzer colors. Unlike other selections, this method is equally sensitive to star-forming and passive galaxies. The first such cluster was confirmed by Papovich et al. (2010). This cluster, IRC0218, has been the target of extensive ground- and space-based observations. I am working on new Hubble WFC3 observations of the cluster which will give us insights on the star formation and stellar build-up in this early, dense environment.
Wong et al., 2014; Lotz et al., 2013; Papovich et al., 2012; Rudnick et al., 2012; Tran et al., 2010; Papovich et al., 2010
3D-HST is a near-infrared spectroscopic survey with the Hubble Space Telescope designed to study the physical processes that shape galaxies in the distant Universe. This Treasury program has been allocated 248 orbits of HST time and is surveying ~600 square arcminutes of well-studied extragalactic survey fields (AEGIS, COSMOS, GOODS-S, UKIDSS-UDS) with two orbits of primary WFC3/G141 (IR) grism coverage and two to four orbits with ACS/G800L (optical) coverage. When completed, 3D-HST would provide the critical third dimension - redshift - for some ~10,000 galaxies at z>1.
As the project manager for the 3D-HST survey, my responsibilities include: coordinating the work of the data reduction and analysis team, overseeing the software development and testing new modules, managing the central server, managing our web-presence, providing support for scientific research, organizing and delivering data releases and compiling accurate documentation.
Strong gravitational lenses occur when the light from a distant source (z>1) is bent from its original path of propagation by the gravitational field of a foreground object (z<1). Strong gravitational lenses ought to be able to provide important constraints for cosmology. This promise, however, has not been met, mainly because the lack of understanding of their large--scale environments has hindered their use. We have carried out a survey of the environments and lines of sight of 28 strong galaxy--mass lenses designed to address this issue. We study the frequency and the effect of groups associated with the lens galaxy as well as line of sight structure, and explore the correlations between the observed lens properties and external perturbations.
We have developped a new observing strategy for wide shallow observations using the WFC3/IR camera on the Hubble Space Telescope. The length of a guide star acquisition by HST limits observations to no more than two pointings per orbit. This limitation can be circumvented by guiding with gyros alone, which is possible as long as the telescope has three functional gyros. Since HST drifts only by ∼ 1/4 WFC3/IR pixel in the 25 seconds between consecutive, non-destructive reads of unguided exposures, the individual reads can be shifted relative to one another and co-added, restoring the full resolution of WFC3. A pilot survey program, COSMOS-DASH (GO-14114, PI: van Dokkum), executed in Cycle 23 will image 0.6 square degrees of the COSMOS field to H(F160W) = 25 in 57 orbits. Mosacis based on the first 4 orbits (32 pointings) are available for download below. This new observing technique is further described in Momcheva et al. (2016) and is now available as part of the Cycle 24 call for proposals.
The 3D-HST team has published four public data releases so far. The most recent release (v4.1.5) contains 2D and 1D spectra, redshifts and emission line fluxes for 10,000 galaxies at z>1. The previous release (v4.1) contains images and catalogs in the five deep extragalactic fields: AEGIS, COSMOS, GOODS-N, GOODS-S and UDS. The data releases are described in Skelton et al. (2014) and Momcheva et al. (2015). The data are currently available for download from the 3D-HST website, while they are being migrated to the MAST archive.
As part of my thesis, I collaborated on a survey of the fields of 28 galaxy-mass strong gravitational lenses. The survey data was collected over 40 nights of 6.5m MMT and Magellan time, employing four different multi-object spectrographs. These observations yielded a redshift catalog of 9768 new and unique galaxy redshifts. 82.4% of the catalog redshifts are between z = 0.1 and z = 0.7, and the catalog median redshift is z = 0.36. The data from this survey can be used to study the lens environments and line-of-sight structures to gain a better understanding of the effects of large scale structure on lens statistics and lens-derived parameters. See Momcheva et al. (2015) for a detailed description of the survey and data.