Dr. Ivelina MomchevaSupport Scientist

Space Telescope Science Institute

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.

Research Interests

  • 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


2017-Now Mission Scientist

Data Science Mission Office, Space Telescope Science Institute, Baltimore, MD

2015-2017 Deputy Group Lead/Support Scientist

WFC3 Instrument Team, Space Telescope Science Institute, Baltimore, MD

2011-2015 Associate Research Scientist/Postdoctoral Researcher

Department of Astronomy, Yale University, New Haven, CT

2004-2009 Research & Teaching Assistant

Department of Astronomy, University of Arizona, Tucson, AZ, USA


2009 Doctor of Philosophy in Astronomy

Department of Astronomy, University of Arizona, Tucson, AZ, USA

2002 Bachelor of Science in Physics

Majors in Astronomy and Optics & spectroscopy

Sofia University "St. Kliment Ohridski", Sofia, Bulgaria

Teaching and Outreach


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.


COSMOS-DASH: A New Method for Wide Field Near-IR Imaging with Hubble

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.

COSMOS-DASH v0.1 Mosaics (351 MB)

Data from the 3D-HST Survey

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.

Go to 3D-HST Data Page

Survey of the Environments of Strong Gravitational Lenses

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.

Download spectroscopic catalogs (1.2MB)