Before, I was a postdoc in the Department of Astronomy at Caltech working with Judy Cohen on tidal streams and the Galactic halo.
I'm interested a lot in the dynamical history of our Milky Way - especially halo formation and the disruption of globular clusters and satellites - , which can tell us a lot about galaxy evolution in general.
As part of my research, I'm developing methods for handling large time-domain survey datasets. I developed astrostatistical and machine-learning methods for fast and reliable detection and classification of variable sources in general, including RR Lyrae and QSOs. Most of my research is based on the Pan-STARRS survey and a subsequent spectroscopically follow-up survey conducted with Keck and Magellan telescopes (The Caltech/Carnegie Survey of the Outer Halo of the Milky Way). For current research, see my publication list.
I'm part of the iPTF/ZTF project and Euclid consortium.
Previously I was a PhD student at Max Planck Institut für Astronomie in Heidelberg, Germany (MPIA), working with Prof. Hans-Walter Rix, Eddie Schlafly and Branimir Sesar. During this time, I was a fellow of the International Max Planck Research School (IMPRS).
contact info
nina [dot] hernitschek [at] vanderbilt [dot] edu
techfreaq [at] web [dot] de
Education
since 2/2017: Postdoc at Caltech
09/2013 to 1/2017: PhD student at MPIA, "Astrophysical Modeling of Time-Domain Surveys", supervisor Hans-Walter Rix
08/2013: M.Sc. Physics, University of Heidelberg, "Estimating Black Hole Masses in Hundreds of Quasars", supervisor Hans-Walter Rix
02/2012: B.Sc. Physics, University of Heidelberg, "Geodesic Lines in Schwarzschild and Kerr Metric", supervisor Matthias Bartelmann
since 2003: worked in several IT projects in industry and research
08/2003: completed 3-year vocational training Fachinformatiker (IHK) (IT specialist, software developer)
Research Assistant
03/2011 - 05/2011: Max-Planck-Institut für medizinische Forschung, Heidelberg: Data analysis
02/2010 - 04/2010: Heidelberg Collaboratory for Image Processing, Universität Heidelberg: software developer for advanced driver assistance systems, robotics
08/2008 - 12/2008: Astronomisches Recheninstitut, Heidelberg: software developer for Gaia
Talks and Conferences
236th AAS Virtual Meeting, June 1 - 3 2020, Virtually Anywhere https://aas.org/meetings/aas236
RRL/Cep 2019 - Frontiers of Classical Pulsators: Theory and Observations, October 13 - 18 2019, Cloudcroft, New Mexico, US http://rrl2019.nmsu.edu SOC, machine-learning workshop
Annual Keck Science Meeting, September 19 - 20 2019, UCLA, Los Angeles, US https://conferences.pa.ucla.edu/keck-2019/
Hot-Wiring the Transient Universe, August 19 - 22 2019, Northwestern University, Evanston (IL), US, talk http://hotwireduniverse.org/
2019 Santa Cruz Galaxy Workshop, August 5 - 9 2019, UCSC, Santa Cruz, US http://hipacc.ucsc.edu/GalaxyWorkshop2019.html
Astroinformatics 2019, June 24 - 27 2019, Caltech Pasadena http://astroinformatics2019.org/
LSST Community Broker Workshop, June 19 - 21 2019, Seattle (WA), US, talk https://project.lsst.org/meetings/cbw/main
NRC Herzberg colloquium talk, Victoria (BC), 6. Nov. 2018
UBC Astronomy colloquium talk, The University of British Columbia, Vancouver (BC), 5. Nov. 2018
Keck Science Meeting, September 20 - 21 2018, Caltech Pasadena, talk http://www.astro.caltech.edu/ksm2018/?utm_source=Keck+Newsletter&utm_campaign=734fe70835-EMAIL_CAMPAIGN_2018_05_11&utm_medium=email&utm_term=0_5a29392474-734fe70835-48147693
The First Caltech-Swinburne Data Science Workshop, September 18 - 19 2018, Caltech http://www.astro.caltech.edu/workshop/
Caltech AI4Science Workshop, August 1 2018, Caltech https://sites.google.com/view/ai-for-science-workshop/
ZTF Summer School 2018, July 18 - 20 2018, Caltech http://www.ztf.caltech.edu/page/ztfss18agenda
The Second Information Universe Conference, July 3 - 6 2018, Groningen, The Netherlands, talk www.informationuniverse.rug.nl talk streaming
Astrophysical Frontiers in the Next Decade and Beyond: Planets, Galaxies, Black holes & the Transient Universe, June 26 - 29 2018, Portland, Oregon, http://www.cvent.com/events/astrophysical-frontiers-in-the-next-decade-and-beyond-planets-galaxies-black-holes-the-transient-uni/event-summary-bc556bd6b79e4ac1be7db2a2177f1725.aspx
Euclid Consortium Meeting, June 11 - 14 2018, Bonn, Germany https://euclid2018.astro.uni-bonn.de/
Statistical Challenges in 21st Century Cosmology, May 22-25 2018, Valencia, Spain, talk http://cosmo21.cosmostat.org/
SnowPAC 2018: Big Questions, Big Surveys, Big Data: Astronomy & Cosmology in the 2020s, March 11-16 2018, Snowbird, Utah, US, talk http://www.physics.utah.edu/snowpac/
Piercing the Galactic Darkness, October 16-19 2017, Heidelberg, Germany http://www2.mpia-hd.mpg.de/galdark2017/
The RR Lyrae 2017 Conference. Revival of the classical pulsators: from galactic structure to stellar interior diagnostics, September 17-21 2017, Niepolomice, Poland, talk https://www.rrl2017.pl/presentations/talk_Hernitschek.pdf http://www.rrl2017.pl
The 3rd Swinburne-Caltech Workshop: Galaxies and their Halos, September 11-12 2017, Caltech, talk http://astronomy.swin.edu.au/research/conferences/swincaltw3/home.html
Euclid Consortium Meeting "100 years of Lambda", June 5–8 2017, London http://euclid2017.london/
Building the Infrastructure for Time-Domain Alert Science in the LSST Era, May 22-25, Tucson, AZ, USA https://www.noao.edu/meetings/lsst-tds/
ZTF Galactic science workshop, March 13-14 March 2017, Caltech
IAU Symposium 325 on Astroinformatics, October 20-24 2016, Sorrento, Italy; award for best poster presentation
IMPRS Summer School "Astrostatistics & Data Mining", September 12-16 2016, Heidelberg, Germany
ESO Munich Joint Conference "Discs in Galaxies", July 11-15 2016, Garching, Germany https://www.eso.org/sci/meetings/2016/Discs2016.html
LSST@Europe2 Conference, June 20-24 2016, Belgrade, Serbia, invited talk https://project.lsst.org/meetings/lsst-europe-2016/
Heidelberg Physics Graduate Days, April 11-15 2016, Heidelberg http://gsfp.physi.uni-heidelberg.de/graddays
RR Lyrae 2015 Conference "High-precision studies of RR Lyrae stars from dynamical phenomena to mapping the galactic structure", 19-22 October 2015, Visegrad, Hungary, invited talk http://rrl2015.hu/
Astro Hack Week 2015, September 28 - October 02, 2015, New York University http://astrohackweek.github.io/
A 3D View on Galaxy Evolution: from Statistics to Physics, July 6-10 2015, MPIA Heidelberg, Germany http://www2.mpia-hd.mpg.de/~galsp2015/
The Local Group Astrostatistics Conference: Bridging Observations & Simulations, MIRA, University of Michigan, June 1 - 4 2015, talk https://www.lsa.umich.edu/mira/workshopsconferences/localgroupastrostatistics
GC Group Retreat, April 21-23 2015, talk
IMPRS seminar retreat, March 2-4 2015, talk
8th HGSFP Winterschool 2015, University Center Obergurgl, January 31 - February 4 2015, poster presentation poster_variability_hernitschek.pdf
2014 Gaia Challenge, Heidelberg, October 27-31 2014
Science Results from Pan-STARRS1, Space Telescope Science Institute Baltimore, June 23-26, talk https://webcast.stsci.edu/webcast/detail.xhtml?talkid=4150&parent=1
Summer Schools in Statistics & Informatics for Astronomers, Penn State University, June 2-13 2014
The Multi-Wavelength, Multi-Epoch Heritage of Stripe 82, Princeton University, March 2014, poster presentation poster_revmap_hernitschek.pdf
The Galaxy, Stellar Compositions and Dynamics, GREAT-ITN School, IAC (Tenerife, Spain), August 2013
Publications
K. Hambleton, F. Bianco, G. Clementini, M. Dall'Ora, R. Egeland5, N. Hernitschek et al., Impact of Rubin Observatory LSST Template Acquisition Strategies on Early Science from the Transients and Variable Stars Science Collaboration: Non-time-critical Science Cases, Research Notes of the AAS, 4, 3 (2020) [AJ]
R. A. Arnold, M. V. McSwain, J. Pepper, N. Hernitschek et. al., Long-Period High-Amplitude Red Variables in the KELT Survey, ApJ 247, 2 (2020) [AJ] [arXiv:2001.06498 [astro-ph.SR]]
D. D. Whitten, T. C. Beers, V. M. Placco, R. M. Santucci, P. Denisenkov, P. B. Tissera, N. Hernitschek, Constraints on inner halo assembly history from identification of blue horizontal-branch age gradient and break radius in the inner halo, ApJ 884, 1 (2019) [AJ] [arXiv:1909.12910 [astro-ph.GA]]
D. C. Masters, D. K. Stern, J. G. Cohen, P. L. Capak, S. A. Standord, N. Hernitschek et al., The complete calibration of the color-redshift relation (C3R2) survey: updates, analysis, and Data Release 2, (2019) , ApJ 877, 2 (2019) [AJ] [arXiv:1904.06394 [astro-ph.GA]]
N. Hernitschek, J. G. Cohen, H.-W. Rix et al., Precision distances to dwarf galaxies and globular clusters from Pan-STARRS1 3π RR Lyrae, ApJ 871, 1 (2019) [AJ] [arXiv:1811.10808 [astro-ph.GA]]
M. A. Fardal, R. P. van der Marel, D. R. Law, S. T. Sohn, B. Sesar, N. Hernitschek, H.-W. Rix, Connecting the Milky Way potential profile to the orbital timescales and spatial structure of the Sagittarius Stream, MNRAS 483, 4 (2019) [MNRAS] [arXiv:1804.04995 [astro-ph.GA]]
P. Capak, D. Sconlic, J-C. Cuillandre, F. Castander, A. Bolton, R. Bowler, C. Chang, A. Dey, T. Eifler, D. Eisenstein, C. Grillmair, P. Gris, N. Hernitschek, et al., Mini-survey of the northern sky to Dec <+30, LSST Survey White Paper Submitted in Dec 2018 [arXiv:1904.10438 [astro-ph.IM]]
N. Hernitschek, J. G. Cohen, H.-W. Rix et al., The Profile of the Galactic Halo from Pan-STARRS1 3π RR Lyrae, ApJ 859, 31 (2018) [ApJ] [arXiv:1801.10260 [astro-ph.GA]]
N. Hernitschek, B. Sesar, H.-W. Rix et al., The Geometry of Sagittarius Stream from Pan-STARRS1 3π RR Lyrae, ApJ 850, 96 (2017) [AJ] [arXiv:1710.09436 [astro-ph.GA]]
B. Sesar, N. Hernitschek, M. I. P. Dierickx et al., The > 100 kpc KPC Distant Spur of the Sagittarius Stream and the Outer Virgo Overdensity, as seen in PS1 RR Lyrae stars, AJ 844, L4 (2017) [AJ] [arXiv:1706.10187]
B. Sesar, N. Hernitschek, S. Mitrović, Z. Ivezić et al., Machine-Learned Identification of RR Lyrae Stars from Sparse, Multi-band Data: the PS1 Sample, AJ 153, 5 (2017) [AJ] [arXiv:1611.08596]
N. Hernitschek, H.-W. Rix, E. F. Schlafly, B. Sesar, D. Hogg, Z. Ivezić et al., Finding, characterizing and classifying variable sources in multi-epoch sky surveys: QSOs and RR Lyrae in PS1 3π data, ApJ 817, 73 (2016) [ApJ] [ADS][arXiv/1511.05527]
N. Hernitschek, H.-W. Rix, J. Bovy, & E. Morganson, Estimating Black Hole Masses in Hundreds of Quasars, ApJ 801, 45 (2015) [ApJ] [ADS] [arXiv/1412.6531]
N. Hernitschek, E. Schmidt, M. Vollmer, Lunar eclipse photometry: absolute luminance measurements and modeling, Appl. Optics 47, 62 (2008) [ADS]
Conference Proceedings
N. Hernitschek, B. Sesar, H.-W. Rix, J. G. Cohen (2018), The Geometry of Sagittarius Stream from Pan-STARRS1 3π RR Lyrae In Radek Smolec, Karen Kinemuchi, Richard Anderson (Eds.), The RR Lyrae 2017 Conference. Revival of the Classical Pulsators: from Galactic Structure to Stellar Interior Diagnostics, Proceedings of the Polish Astronomical Society, vol. 6, pp. 72-76 https://www.pta.edu.pl/proc/v6p72
N. Hernitschek, E. F. Schlafly, B. Sesar et al. (2016), Finding, characterizing and classifying variable sources in multi-epoch sky surveys: QSOs and RR Lyraes in PS1 3π In L. Szabados, R. Szabo, K. Kinemuchi (Eds.), RRL2015 High-Precision Studies of RR Lyrae Stars No. 105 COMMUNICATIONS FROM THE KONKOLY OBSERVATORY OF THE HUNGARIAN ACADEMY OF SCIENCES (pp. 85-92) http://www.konkoly.hu/Mitteilungen/Mitt105/105.pdf
N. Hernitschek, E. F. Schlafly, B. Sesar et al. (2016), Pan-STARRS1 as pilot-survey for panoptic time-domain science. Proceedings of the International Astronomical Union, 12(S325), (pp. 118-121). doi:10.1017/S1743921316012667 https://www.cambridge.org/core/journals/proceedings-of-the-international-astronomical-union/issue/E992FC19B0DD8B57AA4FC2F6B58E3FA6
Teaching
supervising undergraduate student 2018 supervising undergraduate studen 2014 Astrolab 02/2014 - 03/2014
Observing
For The Caltech/Carnegie Survey of the Outer Halo of the Milky Way, I regularly observe with MIKE at Magellan (LCO) and ESI at Keck.
For the Euclid project, I regularly observe with ESI and MOSFIRE at Keck to take spectra for photo-z calibration.