Variability of Accreting White Dwarf Binaries and other Compact Objects

Caltech

AM CVn

Cataclysmic Variables

Manuel Pichardo Marcano (he/him)

AMNH

A Variable Sky

1- SCOVaS: Survey for Compact Objects and Variables

Pichardo Marcano et al. (2021a)

          Pichardo Marcano et al. (submitted)

   Pichardo Marcano et al. (in prep.)

2- TACOS: TESS AM CVn Outbursts Survey

Pichardo Marcano et al. (2021b)

Caltech

NASA

NASA

NGC 6397

• HST Archive
• 7 Globular Clusters
• Many Exposures
• Different properties
  • Metallicity
  • Core-collapsed
  • Non core-collapsed

SCOVaS: Survey for Compact Objects and Variables

Preliminary Results

NGC 6397

• WFPC-2
• March-April 2005:
  • 126 orbits
  • F814W, F606W and F336W
  • Exp time: 500-700 s

Preliminary Results

NGC 6397

• WFPC-2
• March-April 2005:
  • 126 orbits
  • F814W, F606W and F336W
  • Exp time: 500-700 s

A new candidate Redback Pulsar

HUGS catalogue. (Piotto et al. 2015, Nardiello et al. 2018)

Pichardo Marcano et al. (2021a)

X-ray

HST F336W

Radio

Zhao et al. , including Pichardo Marcano (2020)

A new candidate Redback MSP

Pichardo Marcano et. al (2021a)

• P_orb 1.96 days
• Longest P_orb for Redback in GCs
• Missed MSP in Pulsar Searchers

NASA’s Goddard Space Flight Center

Blue Variables

Candidate Magnetic Helium Core White Dwarf in NGC 6397

ESO/L. Calçada

Pichardo Marcano et al. (submitted)

Candidate Magnetic Helium Core White Dwarf in NGC 6397

Pichardo Marcano et al. (submitted)

Candidate Magnetic Helium Core White Dwarf in NGC 6397

ESO/L. Calçada

Pichardo Marcano et al. (submitted)

Transiting Exoplanet Survey Satellite (TESS)

Disk AM CVns

High state (high Ṁ)

• Hot ionized disk

~20

~10

~40-60 (?)

Low state (low Ṁ)

• Cold stable disk

Caltech

Type of Super Outbursts

Osaki et al. (2005)

High Mass Ratio

DIM

Cataclysmic Variables

See also Duffy et al. (2021)

High Mass Ratio

High Mass Ratio

High Mass Ratio

 eccentric disc develops rapidly

Type of Echo Outbursts

SDSS J1043+5632

• P_orb = 28.5 min
• WZ Sge like
  • Precursors
  • EMT (Hameury+'20)
  • Reflection:
    • Hot Massive WD

• P_orb = 26.7 min
• Compare to TCP J21040470+4631129
  • EMT (Hameury+'20)
• Helium "SU UMa"
  • EMT+TTI (Kotko+'12)

SO

rebrightening

SO

rebrightening

Superoutburst duration vs P_orb

Pichardo Marcano et al. (2021)

Other work with Accreting WDs

• Follow-up eROSITA transient:

• TESS time series analysis

• • Atel: Pichardo Marcano (2020)

  • Paper: Schwope, [...], Pichardo Marcano, et al. (2021)

Caltech

Classification of Hot Subdwarfs

• Machine Learning Project:

  • 3 High School Students

Caltech

NASA

Gaia and CV population

Gaia and CV population

Why  Strasbourg?

• Work package 2 : Multi- wavelength/ multi-messenger counterparts:
  • ARCHES
• LSST
  • Fink Broker
• X-rays:
  • eROSITA (AIP)
  • XMM/ Athena

My Skills and Interests

• Time-domain/Big data astronomy
  • ZTF, ATLAS, TESS, HST, Gaia
• Multi-Wavelength
  • X-ray, Radio, Optical, UV
• Experience Transients (CVs)
  • Expand my expertise
• Experience Spectroscopy
  • MUSE, VIMOS, Gemini

Contaminants?

Thank you

Light Curves of Known CV Candidates

High and Low state?

Nova-like Candidate

Pichardo Marcano et. al (in prep)

U19

U21

Nova-like Candidate

Outbursts

Pichardo Marcano et al. (2021)

SO duration

Color Evolution

PTF1 J0719+4858

• Similar to Dwarf Novae

  • Hameury et al. (2020)

• Similar SDSS J1411+4812
  • Rivera Sandoval et al. (2021)
• Compare to SDSS 1137
  • Rivera Sandoval et al. (2021)

Pichardo Marcano et al. (2021)

SDSS J113732+405458

 Enhanced mass transfer

Rivera Sandoval et al. (2021)

P_orb = 26.7 min

P_orb ~ 60 min

Long-term monitoring

• Observed 357 days
• Recurrence Time:
  • 203 days
• P_orb = 30.14 min :
  • 2-minute cadence
• "Normal Outburts"

Sector 5

Sector 12

• Precursor
  • TESS (Duffy et al. 2021)
• 5/6 have Precursor
  • Except ASASSN-14cc

PTF1 J0719+4858

Pichardo Marcano et al. (2021)

ZTF

TESS

Precursor

Color Evolution

PTF1 J0719+4858

SS Cyg

Cataclysmic Variable

• Similar to Dwarf Novae

  • Hameury et al. (2020)

• Similar SDSS J1411+4812
  • Rivera Sandoval et al. (2021)
• Compare to SDSS 1137
  • Rivera Sandoval et al. (2021)

Pichardo Marcano et al. (2021)

NGC 6397

• Pipeline to find interesting objects:
  • CMD Position and Periodicity/Variability Searches
• We were able to recover all known CV Candidates
• Found Orbital Period Redback Pulsar
• Detached White Dwarf-Red Dwarf
• First Magnetic He Core WD in GCs
• Many more variables to analyze...

Interest and Future Work

• Time-domain astronomy
  • ZTF, ATLAS, TESS, HST, Gaia
• Multi-Wavelength:
  • X-ray, Radio, Optica, UV
• Experience Transients
  • Expand my expertise
• Experience Spectroscopy:
  • IFU: MUSE, VIMOS
  • GEMINI

Summary

• Time-domain astronomy
  • ZTF, ATLAS, TESS, HST, Gaia
• Multi-Wavelenght:
  • X-ray, Radio, Optica, UV
• Experience Transients
  • Expand my expertise
• Experience Spectroscopy:
  • IFU: MUSE, VIMOS
  • GEMINI

Compact Binaries Surveys

1- SCOVaS: Survey for Compact Objects and Variables

Pichardo Marcano et al. (2021a)

Pichardo Marcano et al. (in prep.)

2- TACOS: TESS AM CVn Outbursts Survey

Pichardo Marcano et al. (2021b)

Compact Binaries Surveys

Candidate Magnetic Helium Core White Dwarf in NGC 6397

ESO/L. Calçada

Pichardo Marcano et al. (submitted)

NGC 6397

• Pipeline to find interesting objects:
  • CMD Position and Periodicity/Variability Searches
• We were able to recover all known CV Candidates
• Found Orbital Period Redback Pulsar
• Detached White Dwarf-Red Dwarf
• Many more variables to analyze...

X-ray unbiased search

SCOVaS: Survey for Compact Objects and Variables Stars

• HST Archive
• 7 Globular Clusters
• Many Exposures
• Different properties
  • Metallicity
  • Core-collapsed
  • Non core-collapse

SCOVaS: Survey for Studying Compact Objects and Variables

• Focus: Cataclysmic Variables (CVs) with HST
• First Unbiased Survey for CVs in Globular Clusters
  • X-ray faint CVs
  • Orbital Periods
• Spatial Distribution:
  • Looking at the dense Core of Clusters
  • Next: Search in the Outskirts
• Optical Counterpart X-ray/Radio Sources in GCs

Preliminary Results

NGC 6397

• WFPC-2
• March-April 2005:
  • 126 orbits
  • F814W, F606W and F336W
  • Exp time: 500-700 s

Preliminary Results

NGC 6397

• WFPC-2
• March-April 2005:
  • 126 orbits
  • F814W, F606W and F336W
  • Exp time: 500-700 s

A new candidate Redback Pulsar

HUGS catalogue. (Piotto et al. 2015, Nardiello et al. 2018)

Pichardo Marcano et al. (2021a)

X-ray

HST F336W

Radio

Zhao, [...], Pichardo Marcano,  et al. (2020)

A new candidate Redback MSP

Pichardo Marcano et. al (2021a)

• Porb 1.96 days
• Longest Porb for Redback in GCs
• Missed MSP in Pulsar Searchers

Blue Variables

Light Curves of Known CV Candidates

High and Low state?

Nova-like Candidate

Pichardo Marcano et. al (in prep)

U19

U21

Nova-like Candidate

First Magnetic He WD Candidate

Pichardo Marcano et. al (in prep)

Magnetic He WD

• V_rad > 100 km/s (MUSE)
• Not Detected in X-rays
• Rotation Period

  • 18.4 hours 

Pichardo Marcano et. al (in prep)

Pre-Cataclysmic Variable

Pichardo Marcano et. al (in prep)

Detached White Dwarf-Red Dwarf

• Not Detected in X-rays
• Potential P_orb

  • 5.21 hours 

Pichardo Marcano et. al (in prep)

Detached White Dwarf-Red Dwarf

NGC 6397

• Pipeline to find interesting objects:
  • CMD Position and Periodicity/Variability Searches
• We were able to recover all known CV Candidates
• Found Orbital Period Redback Pulsar
• Detached White Dwarf-Red Dwarf
• First Magnetic He Core WD in GCs
• Many more variables to analyze...

Compact Binaries Surveys

1- SCOVaS: Survey for Compact Objects and Variables

Pichardo Marcano et al. (2021a)

Pichardo Marcano et al. (in prep.)

2- TACOS: TESS AM CVn Outbursts Survey

Pichardo Marcano et al. (2021b)

Compact Binaries Surveys

Outbursts

Pichardo Marcano et al. (2021)

• Precursor
  • TESS (Duffy et al. 2021)
• Echo Outbursts
• DIM with Enhanced Mass Transfer  (e.g. Hameury & Lasota 2021)

TESS AM CVn Outbursts Survey

Pichardo Marcano et al. (2021)

ZTF

TESS

Long-term monitoring

Pichardo Marcano et al. (2021)

• Orbital Periods:
  • 2-minute cadence
• Limits on Recurrence Time
• "Normal Outburts"

Superoutburst duration vs P_orb

Pichardo Marcano et al. (2021)

TACOS Summary

• Precursors and "Normal" Outbursts:
  • Relatively Common
  • Short Duration (missed by ground-based)
• Echo Outbursts:
  • Different morphology
  • Enhanced Mass Transfer
• Superoutburst durations overestimated
• Two new candidate orbital periods
• Color Evolution

Preliminary Results

M 92

• WFPC-2
• 2008-01-25 to 2008-01-30:
  • 76 Exposures
  • F555W
  • Exp time: 10 s

New Variables in the Core

SX Phe

• Good Distance indicator:
  • Strong P-L relation
• Less common than RR Lyrae
• Blue Straggler
  • Product of Binary evolution

P = 1.38 hr

Pichardo Marcano et. al (in prep)

Summary

• BlackGEM:
  • Time-domain astronomy
    • ZTF, ATLAS, TESS, HST
  • Experience Transients
    • Expand my expertise
    • Study 'contaminants'
• Experience Spectroscopy:
  • IFU: MUSE, VIMOS
  • GEMINI

Future Work

NGC 6397

M 92

Spectroscopy (MUSE)

AO Gemini IR

Extra Slides

PTF1 J0719+4858:

• Similar to Dwarf Novae:
  • Hameury et al. (2020)
  • Rivera Sandoval et al. (2021)

Color Evolution

Pichardo Marcano et al. (2021)

TACOS Summary

• Precursors and "Normal" Outbursts:
  • Relatively Common
  • Short Duration (missed ground-based)
• Echo Outbursts:
  • Different morphology
  • Enhanced Mass Transfer
• SO durations overestimated
• Two new candidate periods
• Color Evolution

Long-term monitoring

Pichardo Marcano et al. (2021)

• Orbital Periods:
  • 2-minute cadence
• Limits on Recurrence Time
• "Normal Outburts"

Outbursts

Pichardo Marcano et al. (2021)

Transiting Exoplanet Survey Satellite (TESS)

Caltech

• Porb 20 to ~ 60 minutes (?)

• Superoutburts (SO) and "Normal" outbursts (NO)

  • SO: Superhumps (periodic brightness variation )

• Disk instability model (DIM)

  •  Constant Mass transfer rate

  • Tidal-thermal disk instability model

Outbursting Systems

Empirical Relationships

1. Trec prop Porb^7.35
2. Tdur prop Porb^4.54
3. Delta mag prop Porb
4. Long-term
5. Ground-Based:
   1. PTF
   2. CRTS

Levitan et al. 2015

See also Duffy et al. 2021