Dr. Nikole M. Nielsen

Research


The focus of my research is to understand how galaxies form and evolve by examining the properties and motions of gas in the circumgalactic medium (CGM), a massive and diffuse reservoir of gas surrounding galaxies.

Baryon Cycle

I study the baryon cycle, or the flow of gas into and out of galaxies, as cosmological simulations have shown it is vital in regulating galaxy evolution and building up the CGM. Quasar absorption lines due to light from a background quasar piercing the CGM of a foreground galaxy are a powerful tool to obtain detailed gas properties such as the ionization balance, chemical content, density, temperature, and kinematics. By comparing the absorption to the host galaxy properties (color, redshift, orientation, etc.), I determine whether the gas being probed is likely accreting from the intergalactic medium or the CGM (recycled accretion), outflowing from star formation in the galaxy, or being tidally stripped from merging satellite galaxies. This allows me to constrain the role that the baryon cycle plays in galaxy evolution and to test predictions from the simulations.

MAGIICAT

I compiled the MgII Absorber–Galaxy Catalog, or MAGIICAT, which contains both MgII doublet absorption and galaxy data for 182 isolated absorber–galaxy pairs and 29 group environments. We have a series of papers which describe MAGIICAT and look at basic properties of the CGM.

I am now building a new sample at Cosmic Noon (z = 2) to study gas flows when galaxies are most actively building their mass. We recently submitted our first paper with the CGM at Cosmic Noon with KCWI program. We are using the Keck Cosmic Web Imager (KCWI), which is an integral field spectrograph, to identify galaxies at this epoch and HIRES/UVES to analyze their CGM properties in as much detail as at lower redshifts.

DUVET Outflows

I am a leading member of DUVET, whose aim is to test star formation theories, map multiphase outflows, and trace the transfer of gas between the interstellar medium (ISM) and the CGM with KCWI. We target low redshift galaxies that are analogs of z = 1–3 star-forming galaxies and link outflow properties to local star formation rates, star formation efficiencies, gas mass surface densities, and pressures. The outflows we measure in these galaxies will be key to understanding the outflows we measure in the CGM at Cosmic Noon.

I am also a leading member of the Multiphase Galaxy Halos Survey, which studies low redshift
(z < 1) absorber–galaxy pairs with OVI absorption. These data come from a Large program on the Hubble Space Telescope with the Cosmic Origins Spectrograph. Most recently, we examined how the CGM metallicity varies with location about galaxies. We expect to find pristine (low metallicity) gas accreting along galaxy disks and enriched (high metallicity) gas outflowing perpendicular to galaxies. Our work showed the picture is much more complicated.

Curriculum vitae


Education

New Mexico State University, Las Cruces, NM, USA
 Ph.D., Astronomy
  Dissertation: Tracing Galaxy Evolution Through Spatial and
  Kinematic Probes of the MgII Circumgalactic Medium

  Advisor: Christopher W. Churchill
May 2015
 M.S., Astronomy December 2013
Michigan State University, East Lansing, MI, USA
 B.S., Astrophysics
  Advisor: Timothy C. Beers
  Honors College
May 2009

Professional Development


ASTRO 3D Fellow 2021–Present
Postdoctoral Research Associate 2015–2021
 Centre for Astrophysics and Supercomputing
 Swinburne University of Technology, Melbourne, VIC, Australia
Graduate Research Assistant 2009–2015
 Department of Astronomy
 New Mexico State University, Las Cruces, NM, USA
Undergraduate Research Assistant 2008–2009
 Department of Physics and Astronomy
 Michigan State University, East Lansing, MI, USA

Grants and Awards


Highly Commended for Swinburne Vice-Chancellor's Research
 Excellence Award (Early Career)
2019
Highly Commended for Swinburne Vice-Chancellor's Research
 Excellence Award (Early Career)
2017
NMSU Alumni Association Outstanding Graduate Award for
 the Graduate School, Ph.D.
2015
NMSU Astronomy Zia Award for Outstanding Research 2013
ASTRO 3D Covid-19 Extension Grant 2020–2021
NSF East Asia and Pacific Summer Institutes Fellowship at
 Swinburne University of Technology in Melbourne, Australia
2012
NMSU Graduate Research Enhancement Grant, Office of the
 Vice President for Research
2012–2015
New Mexico Space Grant Graduate Research Fellowship 2012
New Mexico Space Grant Graduate Research Fellowship 2010
IAU Travel Grant to IAUS321 2016
NMSU College of Arts and Sciences Graduate Travel Award 2014

Observing


186 HST orbits; 25.5 Keck, 2 Magellan, & 23.5+ APO 3.5m nights; 57.2 hrs VLT; 9.8 hrs ALMA
Awarded Time as PI: HST (WFC3), Keck (MOSFIRE, ESI, NIRC2-LGS)
Awarded Time as Co-I: HST (COS, WFC3), Keck (KCWI, ESI, NIRC2-LGS, NIRES), Magellan (MagE),
 VLT (MUSE, UVES), ALMA, APO 3.5m

Supervising Experience


Co-Supervisor of Swinburne PhD students
  Antonia Fernández-Figueroa2022–Present
  Daniel McPherson2021–Present
  Allison MortonMar 2021–Present
  Hasti NateghiJun 2019–Present
  Stephanie Pointon2016–2019
Supervisor of Swinburne Vacation Scholars
  Megha SharmaDec 2021–Feb 2022
  Rhys DavisDec 2018–Feb 2019
  Mason NgDec 2017–Feb 2018
Mentor to NMSU undergraduate students
  James Lewis2016–2019
  Amber Medina2013–2015
  Mercedes Maldonado2013–2015

Academic Service


Scientific referee for ApJ, ApJ Letters, A&A, MNRAS 2014–Present
External Reviewer for HST's CGM and IGM Panel – – –
Swinburne/CAS Vacation Studentship Organizer Aug 2021–Present
Swinburne/ASTRO 3D All-Melbourne Meeting Organizer Apr 2021–Present
Swinburne/CAS Equity & Diversity Committee Apr 2019–Present
Swinburne Time Allocation Committee for Keck, 3 semesters Apr 2018–Apr 2019
Swinburne/CAS Weekly Scientific Colloquium Series Organizer Aug 2016–Feb 2018
 – Aimed toward a gender-balanced schedule
 – 40% of 2017 speakers were women, up from avg 25% for 2012-2016
Science Organizing Committees
 ASTRO 3D 2020 Science Meeting 2020
 3rd Swinburne–Caltech Workshop: Galaxies and their Halos 2017
 Astronomical Society of Australia 2017 Annual Scientific Meeting 2017
NMSU Astronomy Department Graduate Awards Committee
 Graduate Student Representative
2014–2015
NMSU Astronomy Graduate Student Organization 2009–2015
 President, Faculty–Student Liaison 2011–2012
 Vice President, Department Outreach Coordinator 2010–2011

Professional Memberships


Member of ARC Centre of Excellence ASTRO 3D 2019–Present
Astronomical Society of Australia 2018–Present
American Astronomical Society 2012–2015
Sigma Pi Sigma Physics Honor Society 2009
Society of Physics Students 2005–2009
 President 2008–2009
 Secretary 2007–2008

References


Associate Professor Glenn Kacprzak
Swinburne University of Technology
gkacprzak (at) swin.edu.au
Professor Chris Churchill
New Mexico State University
cwc (at) nmsu.edu
Professor Michael Murphy
CAS Deputy Director
Swinburne University of Technology
mmurphy (at) swin.edu.au
Associate Professor Deanne Fisher
Swinburne University of Technology
dfisher (at) swin.edu.au

Publications — ADS Compilation


Refereed Publications


37. Examining quasar absorption-line analysis methods: the tension between simulations and observational assumptions key to modelling clouds
Marra, R., Churchill, C. W., Kacprzak, G. G., Nielsen, N. M., Trujillo-Gomez, S., & Lewis, J. G. 2022, MNRAS, submitted
36. A Complex Multiphase DLA Associated with a Compact Group at z=2.431 Traces Accretion, Outflows, and Tidal Streams
Nielsen, N. M., Kacprzak, G. G., Sameer, Murphy, M. T., Nateghi, H., Charlton, J. C., & Churchill, C. W. 2022, MNRAS, submitted
35. The DUVET Survey: Resolved Maps of Star Formation Outflows in a Compact, Starbursting Galaxy
Reichardt Chu, B., Fisher, D. B., Nielsen, N. M., Chisholm, J., Girard, M., Kacprzak, G. G., Bolatto, A., Herrera-Camus, R., Sandstrom, K., Li, M., Rickards Vaught, R., & McPherson, D. K. 2022, MNRAS, accepted
34. Extreme Variation in Star Formation Efficiency across a Compact, Starbursting Disk Galaxy
Fisher, D. B., Bolatto, A. D., Glazebrook, K., Obreschkow, D., Abraham, R. G., Kacprzak, G. G., & Nielsen, N. M. 2022, ApJ, accepted
33. Probing the physicochemical properties of the Leo Ring and the Leo I group
Sameer, Charlton, J. C., Kacprzak, G. G., Narayanan, A., Sankar, S., Richter, P., Wakker, B. P., Nielsen, N. M., & Churchill, C. W. 2022, MNRAS, 510, 5796
32. Evolution of CIV Absorbers. II. Where does CIV live?
Hasan, F., Churchill, C. W., Stemock, B., Nielsen, N. M., Kacprzak, G. G., Croom, M., & Murphy, M. T. 2022, ApJ, 924, 12
31. Using cosmological simulations and synthetic absorption spectra to assess the accuracy of observationally derived CGM metallicities
Marra, R., Churchill, C. W., Doughty, C., Kacprzak, G. G., Charlton, J. C., Sameer, Nielsen, N. M., Ceverino, D., & Trujillo-Gomez, S. 2021, MNRAS, 508, 4938
30. The DUVET Survey: Direct Te-based Metallicity Mapping of Metal-enriched Outflows and Metal-poor Inflows in Markarian 1486
Cameron, A. J., Fisher, D. B., McPherson, D., Kacprzak, G. G., Berg, D. A., Bolatto, A., Chisholm, J., Herrera-Camus, R., Nielsen, N. M., Reichardt Chu, B., Rickards Vaught, R. J., Sandstrom, K, & Trenti, M. 2021, ApJL, 918, L16
29. Spatial Distribution of OVI Covering Fractions in the Simulated Circumgalactic Medium
Marra, R., Churchill, C. W., Kacprzak, G. G., Vander Vliet, R. P., Ceverino, D., Lewis, J. G., Nielsen, N. M., Muzahid, S., & Charlton, J. C. 2021, ApJ, 907, 8
28. Cloud-by-cloud, multiphase, Bayesian modeling: Application to four weak, low ionization absorbers
Sameer, Charlton, J. C., Norris, J. M., Gebhardt, M., Churchill, C. W., Kacprzak, G. G., Muzahid, S., Narayanan, A., Nielsen, N. M., Richter, P., & Wakker, B. 2021, MNRAS, 501, 2112
27. Disentangling the multi-phase circumgalactic medium shared between a dwarf and a massive star-forming galaxy at z~0.4
Nateghi, H., Kacprzak, G. G., Nielsen, N. M., Muzahid, S., Churchill, C. W., Pointon, S. K., & Charlton, J. C. 2021, MNRAS, 500, 3987
26. Evidence for galaxy quenching in the green valley caused by a lack of a circumgalactic medium
Kacprzak, G. G., Nielsen, N. M., Nateghi, H., Churchill, C. W., Pointon, S. K., Nanayakkara, T., Muzahid, S., & Charlton, J. C. 2021, MNRAS, 500, 2289
25. The CGM at Cosmic Noon with KCWI: Outflows from a Star-forming Galaxy at z=2.071
Nielsen, N. M., Kacprzak, G. G., Pointon, S. K., Murphy, M. T., Churchill, C. W., & Davé, R. 2020, ApJ, 904, 164
24. Evolution of CIV Absorbers. I. The Cosmic Incidence
Hasan, F., Churchill, C. W., Stemock, B., Mathes, N. L., Nielsen, N. M., Finlator, K., Doughty, C., Croom, M., Kacprzak, G. G., & Murphy, M. T. 2020, ApJ, 904, 44
23. MgII Absorbers in High-Resolution Quasar Spectra. I. Voigt Profile Models
Churchill, C. W., Evans, J. L., Stemock, B., Nielsen, N. M., Kacprzak, G. G., & Murphy, M. T. 2020, ApJ, 904, 28
22. Low-mass Group Environments Have No Substantial Impact on the Circumgalactic Medium Metallicity
Pointon, S. K., Kacprzak, G. G., Nielsen, N. M., Murphy, M. T., Muzahid, S., Churchill, C. W., & Charlton, J. C. 2020, AJ, 159, 216
21. The Relationship between Galaxy ISM and Circumgalactic Gas Metallicities
Kacprzak, G. G., Pointon, S. K., Nielsen, N. M., Churchill, C. W., Muzahid, S., & Charlton, J. C. 2019, ApJ, 886, 91
20. Kinematics of the OVI Circumgalactic Medium: Halo Mass Dependence and Outflow Signatures
Ng, M., Nielsen, N. M., Kacprzak, G. G., Pointon, S. K., Muzahid, S., Churchill, C. W., & Charlton, J. C. 2019, ApJ, 886, 66
19. Relationship between the Metallicity of the Circumgalactic Medium and Galaxy Orientation
Pointon, S. K., Kacprzak, G. G., Nielsen, N. M., Muzahid, S., Murphy, M. T., Churchill, C. W., & Charlton, J. C. 2019, ApJ, 883, 78
18. Io's Volcanic Activity from Time Domain Adaptive Optics Observations: 2013-2018
de Kleer, K., de Pater, I., Molter, E. M., Banks, E., Davies, A. G., Alvarez, C., Campbell, R., Aycock, J., Pelletier, J., Stickel, T., Kacprzak, G. G., Nielsen, N. M., Stern, D., & Tollefson, J. 2019, AJ, 158, 29
17. The Relation between Galaxy ISM and Circumgalactic OVI Gas Kinematics Derived from Observations and ΛCDM Simulations
Kacprzak, G. G., Vander Vliet, R. P., Nielsen, N. M., Muzahid, S., Pointon, S. K., Churchill, C. W., Ceverino, D., Arraki, K. S., Klypin, A., Charlton, J. C., & Lewis, J. 2019, ApJ, 870, 137
16. MAGIICAT VI. The MgII Intragroup Medium is Kinematically Complex
Nielsen, N. M., Kacprzak, G. G., Pointon, S. K., Churchill, C. W., & Murphy, M. T. 2018, ApJ, 869, 153
15. The Impact of the Group Environment on the OVI Circumgalactic Medium
Pointon, S. K., Nielsen, N. M., Kacprzak, G. G., Muzahid, S., Churchill, C. W., & Charlton, J. C. 2017, ApJ, 844, 23
14. The Highly Ionized Circumgalactic Medium is Kinematically Uniform Around Galaxies
Nielsen, N. M., Kacprzak, G. G., Muzahid, S., Churchill, C. W., Murphy, M. T., & Charlton, J. C. 2017, ApJ, 834, 148
13. MAGIICAT IV. Kinematics of the Circumgalactic Medium and Evidence for Quiescent Evolution Around Red Galaxies
Nielsen, N. M., Churchill, C. W., Kacprzak, G. G., Murphy, M. T., & Evans, J. L. 2016, ApJ, 818, 171
12. The Azimuthal Dependence of Outflows and Accretion Detected Using OVI Absorption
Kacprzak, G. G., Muzahid, S., Churchill, C. W., Nielsen, N. M., & Charlton, J. C. 2015, ApJ, 815, 22
11. MAGIICAT V. Orientation of Outflows and Accretion Determine the Kinematics and Column Densities of the Circumgalactic Medium
Nielsen, N. M., Churchill, C. W., Kacprzak, G. G., Murphy, M. T., & Evans, J. L. 2015, ApJ, 812, 83
10. An Extreme Metallicity, Large-Scale Outflow from a Star-Forming Galaxy at z~0.4
Muzahid, S., Kacprzak, G. G., Churchill, C. W., Charlton, J. C., Nielsen, N. M., Mathes, N. L., & Trujillo-Gomez, S. 2015, ApJ, 811, 132
9. Halo Mass Dependence of HI and OVI Absorption: Evidence for Differential Kinematics
Mathes, N. L., Churchill, C. W., Kacprzak, G. G., Nielsen, N. M., Trujillo-Gomez, S., Charlton, J., & Muzahid, S. 2014, ApJ, 792, 128
8. MAGIICAT III. Interpreting Self-Similarity of the Circumgalactic Medium with Virial Mass Using MgII Absorption
Churchill, C. W., Trujillo-Gomez, S., Nielsen, N. M., & Kacprzak, G. G. 2013, ApJ, 779, 87
7. The Smooth MgII Gas Distribution Through the Interstellar/Extra-planar/Halo Interface
Kacprzak, G. G., Cooke, J., Churchill, C. W., Ryan-Weber, E. V., & Nielsen, N. M. 2013, ApJ, 777, L11
6. MAGIICAT I. The MgII Absorber-Galaxy Catalog
Nielsen, N. M., Churchill, C. W., Kacprzak, G. G., & Murphy, M. T. 2013, ApJ, 776, 114
5. MAGIICAT II. General Characteristics of the MgII Absorbing Circumgalactic Medium
Nielsen, N. M., Churchill, C. W., & Kacprzak, G. G. 2013, ApJ, 776, 115
4. The Redshift Distribution of Intervening Weak MgII Quasar Absorbers and a Curious Dependence on Quasar Luminosity
Evans, J. L., Churchill, C. W., Murphy, M. T., Nielsen, N. M., & Klimek, E. S. 2013, ApJ, 768, 3
3. The Self-Similarity of the Circumgalactic Medium with Galaxy Virial Mass: Implications for Cold-Mode Accretion
Churchill, C. W., Nielsen, N. M., Kacprzak, G. G., & Trujillo-Gomez, S. 2013, ApJ, 763, L42
2. Tracing Outflows and Accretion: A Bimodal Azimuthal Dependence of MgII Absorption
Kacprzak, G. G., Churchill, C. W., & Nielsen, N. M. 2012, ApJ, 760, L7
1. Quenched Accretion of a Large Scale Metal-Poor Filament due to Virial Shocking in the Halo of a Massive z=0.7 Galaxy
Churchill, C. W., Kacprzak, G. G., Steidel, C. C., Spitler, L. R., Holtzman, J. A., Nielsen, N. M., & Trujillo-Gomez, S. 2012, ApJ, 760, 68

Conference Proceedings


3. Gas Kinematics in the Multiphase Circumgalactic Medium
Nielsen, N. M., Kacprzak, G. G., Churchill, C. W., Murphy, M. T., Muzahid, S., Charlton, J. C., & Evans, J. L. 2017, in IAU Symposium 321, Formation and Evolution of Galaxy Outskirts, ed. A. Gil de Paz, J. H. Knapen, & J. C. Lee, 345
2. HST Observations Reveal the Curious Geometry of Circumgalactic Gas
Kacprzak, G. G., Muzahid, S., Churchill, C. W., Nielsen, N. M., & Charlton, J. C. 2017, in IAU Symposium 321, Formation and Evolution of Galaxy Outskirts, ed. A. Gil de Paz, J. H. Knapen, & J. C. Lee, 342
1. HST Observations Reveal the Curious Geometry of Circumgalactic Gas
Kacprzak, G. G., Muzahid, S., Churchill, C. W., Nielsen, N. M., & Charlton, J. C. 2016, in The Interplay between Local and Global Processes in Galaxies, ed. S. F. Sanchez, C. Morisset, & G. Delgado-Inglada, 26

Conferences and Colloquia


Conferences


– What matter(s) around galaxies 2022 in The Alps, Italy Sep 2022 Invited Talk
– Keck Science Meeting (zoom) Sep 2021 Talk
– ASTRO 3D 2021 Science Meeting (zoom) Sep 2021 Sprint Talk
– KITP Program Fundamentals of Gaseous Halos (zoom) Jan 2021 Talk
Spatially Resolved CGM Emission in a Nearby Starbursting
  Galaxy with DUVET
Outflows from a Star-forming Galaxy at z=2.071 with KCWI
– CGM@ND Workshop in Dublin and Kylemore, Ireland Postponed Invited Talk
– Multiphase Gas in Galaxy Groups Workshop in Charlottesville,
 Virginia, USA
Postponed Invited Talk
– CGM Berlin 2019 in Berlin, Germany Oct 2019 Invited Talk
– 2nd KIAA Forum on Gas in Galaxies in Beijing, China Sep 2019 Invited Talk
– Astronomical Society of Australia Annual Scientific Meeting in
 Brisbane, Australia
Jul 2019 Talk
– Australia–ESO Joint Conference: Linking Galaxies from the
 Epoch of Initial Star Formation to Today in Sydney, Australia
Feb 2019 Talk
– Intergalactic Interconnections in Marseille, France Jul 2018 Talk
– Astronomical Society of Australia Annual Scientific Meeting in
 Melbourne, Australia
Jun 2018 Poster
– Keck Science Meeting 2017 in Santa Cruz, CA Sep 2017 Talk
– The 3rd Swinburne-Caltech Workshop: Galaxies and their Halos
 in Pasadena, CA
Sep 2017 Talk
– The Circle of Life: Connecting the Intergalactic, Circumgalactic,
 and Interstellar Media in Kruger Park, South Africa
Aug 2017 Talk
– What Matter(s) Around Galaxies in Durham, UK Jun 2017 Talk
– ITSO Science Symposium 2017 in Canberra, Australia May 2017 Talk
– Crossing the Rubicon in Santarcangelo di Romagna, Italy Sep 2016 Talk
– IAUS 321 Formation and Evolution of Galaxy Outskirts in Toledo,
 Spain
Mar 2016 Talk
– 225th American Astronomical Society Meeting in Seattle, WA Jan 2015 Talk
– Santa Cruz Galaxy Workshop in Santa Cruz, CA Aug 2014 Talk
– Intergalactic Matters in Heidelberg, Germany Jun 2014 Talk
– The Near-Field Deep-Field Connection in Irvine, CA Feb 2014 Poster
– The Physical Link Between Galaxies and their Halos in Garching,
 Germany
Jun 2013 Poster
– Leiden Summer CGM–Galaxy Interface Workshop in Leiden,
 Netherlands
Jun 2013 Talk
– The 28th New Mexico Symposium in Socorro, NM Nov 2012 Talk
– STScI May Symposium: Gas Flows in Galaxies in Baltimore, MD May 2012 Poster
– 219th American Astronomical Society Meeting in Austin, TX Jan 2012 Poster

Colloquia


ICRAR/UWA Seminar Apr 2022 Invited Talk
University of Melbourne Astrophysics Seminar Apr 2021 Invited Talk
OUTAP Colloquium at Osaka University Nov 2020 Invited Talk
Cosmology-Galaxy-IGM Seminar at UC Santa Cruz Oct 2020 Invited Talk
NMSU Astronomy Department Colloquium Sep 2020 Invited Talk
Sydney Institute for Astronomy Seminar, University of Sydney Postponed Invited Talk
ICRAR/UWA Seminar in Perth, Australia Postponed Invited Talk
ASTRO 3D Zoom Colloquium Series Oct 2019 Invited Talk
Swinburne Research Conference ECR Panel May 2018 Invited Panel
Swinburne Director's Lunch Talk Feb 2018 Invited Talk
Swinburne ASTRO 3D Lunch Talk Jun 2017 Invited Talk
University of Melbourne Astrophysics Seminar May 2017 Invited Talk
NMSU Astronomy Department Colloquium Mar 2015 Talk
NMSU Graduate Research and Arts Symposium Mar 2015 Poster
NMSU Astronomy Department Pizza Lunch Sep 2014 Talk
NMSU Graduate Research and Arts Symposium Mar 2014 Poster
NMSU Astronomy Department Colloquium May 2013 Talk
NMSU Astronomy Department Pizza Lunch Oct 2012 Talk
NMSU Graduate Research and Arts Symposium Mar 2012 Poster