Science Briefing October 8 2020 Dr Vanessa Graber

Science Briefing October 8, 2020 Dr. Vanessa Graber Institute of Space Sciences (ICE-CSIC) The Magnetic Universe Dr. Enrique Lopez Rodriguez Observatory for Infrared Astronomy (SOFIA), NASA Ames Facilitator: Dr. Kelly Lepo Space Telescope Science Institute

Outline of this Science Briefing 1. Dr. Kelly Lepo Space Telescope Science Institute Magnetic Fields in Space 2. Dr. Vanessa Graber Institute of Space Sciences (ICE-CSIC) Neutron stars: the strongest magnets in the Universe 3. Dr. Enrique Lopez Rodriguez Observatory for Infrared Astronomy (SOFIA), NASA Ames Magnetic fields in galaxy evolution 4. Q & A 5. Dr. Kelly Lepo Space Telescope Science Institute Science and Education Resources 6. Q & A 2

Magnetic Fields In Space A brief introduction to our magnetic Universe

Iron Filings Trace Magnetic Field Lines Credit: F. Austin Credit: Jan. Der. Chemiker/Wikimedia Commons 4

Plasma Traces Magnetic Field Lines on the Sun Credit: NASA/SDO and the AIA, EVE, and HMI science teams 5

Magnetic Fields Around Other Stars Credit: Pascalou petit/Wikimedia Commons 6

Magnetic Fields Influence Star Formation Credit: NASA/ESA/Hubble Heritage Team (STSc. I/AURA), Pattle et al. 2018 7

Dust Traces Magnetic Field Lines in our Galaxy Credit: ESA and the Planck Collaboration 8

Magnetic Bridge Between Two Galaxy Clusters Credit: F. Govoni and M. Murgia (Italy National Institute for Astrophysics) 9

Magnetic Fields Make Jets 0. 25 ly Credit: NASA, ESA, the Hubble Heritage Team (STSc. I/AURA) 500, 000 ly Credit: NASA, ESA, S. Baum and C. O'Dea (RIT), R. Perley and W. Cotton (NRAO/AUI/NSF), and the Hubble Heritage Team (STSc. I/AURA) 10

Neutron Stars: The Strongest Magnets in the Universe Dr. Vanessa Graber Institute of Space Sciences (ICE-CSIC), Barcelona 11

Neutron Star Formation • At the end of their lives, very massive stars explode in so-called supernovae, leaving behind gigantic remnants. Crab Nebula, 1054 A. D. Credit: NASA, ESA, J. Hester, A. Loll (ASU) Cassiopeia A, ~1670 A. D. Credit: NASA, JPL-Caltech, STSc. I, CXC, SAO 12

Neutron Star Sizes and Masses • Neutron stars have sizes that are comparable to a city. Credit: Google, Fff ESO, L. Calçada Credit: NASA, SDO • Their masses are comparable to that of the Sun. 13

Neutron Star Discovery • They were first observed by Jocelyn Bell Burnell in 1967. • The source, which repeated regularly at a period of 1. 3 s, Credit: J. Bell Burnell was (jokingly) called LGM-1. 14

Neutron Star Discovery • They were first observed by Jocelyn Bell Burnell in 1967. • The source, which repeated regularly at a period of 1. 3 s, was (jokingly) called LGM-1. 15

Neutron Star Rotation • These regular signals arise due to fast rotation and extremely strong magnetic fields. • Neutron stars spin up to ~700 times per second. 16

Neutron Star Magnetic Fields • Neutron stars are the strongest magnets in the Universe. --- • Their fields are a trillion times stronger than the Earth's magnetic field. Credit: ESO, L. Calçada 17

Neutron Star Magnetic Fields • The magnetic field on large scales is dominated by its dipolar nature. • --- • The field lines resemble those of magnets with a north and south pole. -- Credit: N. H. Black, H. N. Davis 18

Neutron Star Magnetic Fields • Particles are accelerated along the open field lines and emit radiation. --- • The rotation and magnetic field axes do not coincide but form an angle. Credit: ESO, L. Calçada 19

Neutron Star Magnetic Fields • Neutron stars emit radio waves similar to the way a lighthouse emits light. • --- • This causes regular radio emission of many neutron stars, so-called pulsars. Credit: J. Christiansen 20

Pulses as Diagnostic Tools • By studying pulse shapes, we can e. g. learn more about the emission cone's structure and the magnetic field itself. • The difference in arrival time between two pulses teaches us about internal mechanisms that affect the neutron star rotation. Credit: Factory Records 21

Neutron stars are the strongest magnets in the Universe and the perfect laboratory to study matter under extreme conditions. 22

Extragalactic magnetism ENRIQUE LOPEZ RODRIGUEZ SOFIA AT NASA AMES 23

The universe looks about the same no matter where you are within it Illustris. TNG Team Matter is distributed evenly at very large scales in the universe 24

Galaxy Evolution amplifies magnetic fields Galaxy evolution is controlled by a delicate interplay between dark matter, gravity, feedback, turbulence, and magnetic fields Marinacci et al. (2018) Stage 1: Field seeds - Generation of seed fields by Biermann battery, Weibel instability, or plasma fluctuations. (B~10 -18 - 10 -6 G) Stage 2: Field Amplification - Amplification of seed fields by turbulent gas flows, i. e. small-scale dynamo (B~10 -5 G). - Turbulence is driven by accretion flows and SN explosions. Stage 3: Field ordering - Field ordered (stretched) by shear and by large-scale dynamo (t~10 9 yr) - Turbulence driven by SN explosions and magnetorotational instabilities (MRI) in galaxy disks. 25

Magnetic fields in galaxies Early-type galaxies (elliptical and irregular) have irregular magnetic fields. - High velocity dispersion (high turbulence field) - Not enough time for the magnetic field to become organized or amplified Disk galaxies (spiral galaxies) have regular large-scale magnetic fields. - Low velocity dispersion (low turbulence field) - Late-type galaxies with enough time for the dynamo to take place and amplify the magnetic fields Marinacci et al. (2018) FACE-on Edge-on Face-on edge-on Starlight Velocity Field Magnetic Field 26

Open questions Is the intergalactic medium magnetized? How do magnetic fields affect the evolution of galaxies in mergers? How have the fields been amplified in galaxies? 27

HAWC+ Onboard SOFIA detects Magnetic Fields HAWC+: Far-Infrared Polarimeter SOFIA: 2. 7 -m telescope WAVELENGTH RANGE: 0. 3 -600 microns INSTRUMENTS: 5 instruments: cameras, spectrometers, high-spectrometers, and imager-polarimeter AIRSPEED: Mach 0. 85 (560 mph ~ 901 kmh) OBSERVING ALTITUDE: 37, 000 - 45, 000 ft ONBOARD STAFF: Flight crew 3; Mission crew 2 -6, Scientists 1 -3, Educators 5 -15 AVERAGE SCIENCE FLIGHT LENGTH: 10 hours overnight 28

The magnetic fields are dragged by galactic outflows ~700 pc 53 um HAWC+ observations M 82: Starburst galaxy Jones, Dowell, Lopez-Rodriguez et al. (2019) 29

Regular magnetic fields are tightly aligned with spiral arms ~3 kpc 89 um HAWC+ observations NGC 1068: Grand-design spiral galaxy Lopez-Rodriguez et al. (2020 a) 30

The magnetic fields follow the warped disk and are highly perturbed ~3 kpc 89 um HAWC+ HAWC observations Centaurus A: Merger galaxy Lopez-Rodriguez (2020 c, Nature Astronomy) 31

SOFIA Heralds a New Era of Measuring Extragalactic Magnetic Fields • Magnetic fields are ubiquitous at all scales in the universe • Galaxy evolution is controlled by a delicate interplay between dark matter, gravity, feedback, turbulence, and magnetic fields • Using SOFIA observations, we found: • Galactic outflows magnetize the intergalactic medium • Galaxy interaction enhances small-scale fields • Late-type galaxies have regular large-scale fields tightly aligned with the recent star formation regions along the spiral arms • Magnetic fields affect galaxy evolution 32

Additional Resources- Magnetism and the Sun • Solar Dynamics Observatory – Resources for Educators • https: //sdo. gsfc. nasa. gov/epo/educators/resources. php • NASA: Understanding the Magnetic Sun video • https: //www. nasa. gov/feature/goddard/2016/ understanding-the-magnetic-sun • Exploring Magnetism in Solar Flares – Activity Guide • http: //cse. ssl. berkeley. edu/SEGwayed/lessons/exploring_ magnetism/in_Solar_Flares/index. html • NASA Space Place: The Sun • https: //spaceplace. nasa. gov/menu/sun/ 33

Additional Resources- SOFIA • Scientific Observations Gallery • https: //www. sofia. usra. edu/multimedia/image-gallery/scientific-observations • Magnetic Fields in Galaxies • How to Shape a Spiral Galaxy https: //www. nasa. gov/feature/how-to-shape-a-spiral-galaxy • Magnetic Fields Force New Perspective on the Center of Our Milky Way Galaxy https: //www. nasa. gov/feature/magnetic-fields-force-new-perspective -on-the-center-of-our-milky-way-galaxy • Active Astronomy: Classroom Activities • https: //www. sofia. usra. edu/multimedia/sofia- outreach/outreach-and-public-engagement-supportmaterials/active-astronomy 34

Additional Resources- Neutron Stars • In a Different Light: The Crab Nebula – View. Space Video • https: //viewspace. org/video_library/videos/ 784 -STSc. I_VS_Ia. DL_Crab. Nebula_1920 x 1080 -354729997 • Images of Neutron Stars: • Astropix: https: //astropix. ipac. caltech. edu/link/d 85 • Hubble. Site: https: //hubblesite. org/resource-gallery/ images? keyword=Neutron%20 Stars • Chandra X-Ray Observatory: https: //chandra. harvard. edu/photo/category/neutronstars. html • Fermi and XMM-Newton: Supernova Educator Unit • https: //xmm. sonoma. edu/supernova/index. html 35

Additional Resources- Other Magnetism Resources • Exploring Magnetism • http: //cse. ssl. berkeley. edu/SEGwayed/lessons/ exploring_magnetism/Exploring_Magnetism/index. html • Neato-Magneto Planets and Investigating the Insides Activities • https: //www. lpi. usra. edu/education/explore/ solar_system/activities/neato. Magneto/ • https: //www. lpi. usra. edu/education/explore/ solar_system/activities/insides/ • Astro. Pix: Magnetic Fields • https: //astropix. ipac. caltech. edu/link/d 83 36

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