Pulsar and Magnetar Astronomy
Pulsar and magnetar astronomy are two fascinating subfields of neutron star research in astrophysics. DSES is active in this area and has detected many pulsars and one magnetar.
Pages describing specific results will be here soon.
Here’s an overview:
Pulsars
- Definition: Pulsars are rapidly rotating neutron stars that emit beams of electromagnetic radiation from their magnetic poles. As these beams sweep past Earth, they appear as regular pulses of radio, optical, X-ray, or gamma-ray emission—hence the name “pulsar.”
- Discovery: First discovered in 1967 by Jocelyn Bell Burnell and Antony Hewish.
- Properties:
- Extremely dense remnants of massive stars that exploded as supernovae.
- Rotate very quickly (milliseconds to seconds per rotation).
- Have strong magnetic fields (10^8–10^13 Gauss).
- Astronomical Importance:
- Used as cosmic clocks due to their precise periodicity.
- Help test theories of gravity (e.g., through binary pulsar systems).
- Can probe the interstellar medium via pulse dispersion.
Magnetars
- Definition: Magnetars are a special type of neutron star with magnetic fields much stronger than ordinary pulsars—up to 10^14–10^15 Gauss.
- Discovery: Recognized as a separate class in the late 1990s; originally observed as soft gamma repeaters (SGRs) and anomalous X-ray pulsars (AXPs).
- Properties:
- Magnetic fields a thousand times stronger than typical pulsars.
- Often emit short bursts of X-rays or gamma-rays.
- Their strong magnetic field can distort atoms and even the crust of the neutron star, causing starquakes and bursts of high-energy radiation.
- Astronomical Importance:
- Offer insights into the physics of extreme magnetic fields.
- Are linked to mysterious phenomena like Fast Radio Bursts (FRBs).
- Help understand the end stages of stellar evolution and the behavior of matter at nuclear densities.
Key Differences
| Feature | Pulsars | Magnetars |
|---|---|---|
| Magnetic Field | 10^8–10^13 Gauss | 10^14–10^15 Gauss |
| Main Emission | Radio (most), some X-ray | X-ray, gamma-ray |
| Stability | Highly stable (timing) | Less stable, prone to flares |
| Rarity | More common | Rarer (~30 known) |
Astronomy Applications
- Both: Help understand the life cycle of stars, stellar remnants, and the behavior of matter under extreme conditions.
- Pulsars: Used for navigation, testing general relativity, and probing galactic structure.
- Magnetars: Studied for their energetic outbursts and possible connection to high-energy astrophysical phenomena.
21cm Neutral Hydrogen Astronomy
DSES has science observations for 21cm neutral hydrogen. These were tracked for several minutes, so not the same as drift scan.