1- AM CVns: 9 Eclipsing

WD Binaries

TESS

2- Compact Binaries in Globular Clusters

HST

Magnetic Helium Core WDs?

3- Symbiotics. TESS and KELT?

TESS

4-LC features

1-Feets

2-tsfresh

3-kats

4-hctsa

Finding CVs in X-rays and UV

• Advantages of X-ray Searches:

  • Avoid crowding

• Disadvantages:

  • Small FoV (FUV)
  • Lx ≥ 10²⁹ ergs/s

Summary CVs in GCs

• Few of CVs per cluster

• X-ray biased sample:

  • Lx > 10²⁹ergs/s

• Predicted "Hidden" Population:

  • Belloni et al. (2016, 2017a, 2017b)

• Dearth of DNe:

  • Only 17 confirmed

• Core-collapsed:

  • Bimodal population

• Period distribution?

  • ~15 known periods

All Magnetics ?

See Belloni & Rivera Sandoval (2020) and Rivera Sandoval et al. (2024)

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

SCOVaS: Survey for Compact Objects and Variables

NGC 6397

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

Light Curves Variable WD Candidates

5.3 hours

ESO/L. Calçada

Magnetic Fields?

To do: Finish the introduction and send it to co-authors

New To do: Finish new comments from co-authors and resend

Why it took me so long?

• I don't love writing:
• Procrastination

Future Plans:

• Submit to Journal by end of Summer?
• ESO proposal  Sept, 2024

SCOVaS: Survey for Compact Objects and Variables

TESS and AM CVns

LILA and

SN

White Dwarf Mergers LILA/LISA

White Dwarf Mergers LILA/LISA

White Dwarf Mergers LILA/LISA

White Dwarf Mergers LILA/LISA

To do: SNR GLOC, LILA, etc.

Why I haven't done it?

• Very bad at multi-tasking

When I hope to do it:

• Have all the figures by Summer ?

MARES: Magnetic Remnants in Symbiotics

To do: Resubmit TESS proposal

New to Do:

• Data Analysis
• Gaussian process

Why I haven't done it?

• Other projects more intersting right now
• Bad at multi-tasking

When I hope to do it:

• I don't know
• I would love to learn about Gaussian Process for this project and others.

What is the percentage of magnetic WDs in Symbiotics? (Merc et al. 2023, Belloni et al. 2024)

Future Stuff I would love to Brainstorm

• Compact Object Population in Old Open Clusters (OOC)
  • LISA Sources?
  • Extremely Low Mass WDs in OOC
    • Single Stellar Evolution

Extra

Future Stuff:

Data from Peters (2008)

• Halo vs Thick Disk:
  • Halo CVs:
    • Not Period Bouncers
  • Halo AM CVns

1- CVs in the Halo

2-WDs mergers in the LILA band

WDs Merger

Summary CVs in GCs

• Few of CVs per cluster

• X-ray biased sample:

  • Lx > 10²⁹ergs/s

• Predicted "Hidden" Population:

  • Belloni et al. (2016, 2017a, 2017b)

• Dearth of DNe:

  • Only 17 confirmed

• Core-collapsed:

  • Bimodal population

• Period distribution?

  • ~15 known periods

All Magnetics ?

See Review by Belloni & Rivera Sandoval (2020) arxiv:2008.12772

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

PTF1 J0719+4858

Pichardo Marcano et al. (2021)

ZTF

TESS

Precursor

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

• Color Evolution

PTF1 J0719+4858

Pichardo Marcano et al. (2021)

ZTF

SO

NO

SO

NO

rebrightening

rebrightening

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

Superoutburst duration vs P_orb

Pichardo Marcano et al. (2021)

Cataclysmic Variables

• White dwarf primary

• "Main-sequence" donor

• Roche-lobe overflow

• Accretion disk (non-magnetic)

• Highly Variables:

  • Dwarf novae

    • 2-8 mag outburst

    • 10-100 increase in L

Looking of CVs in GCs

NASA, ESA, H. Richer and J. Heyl (University of British Columbia), and J. Anderson and J. Kalirai (STScI)

Ṁ of AM CVns:

To do: À la Schreiber et al. ('07,02) knowing the Gaia distance, calculate Ṁ and compare to models

Why I haven't done it?

• Still not sure how
• Time

When I hope to do it:

• Before Euro WD Conf.  July 8th to 12th

Finding CVs in X-rays and UV

• Advantages of X-ray Searches:

  • Avoid crowding

• Disadvantages:

  • Small FoV (FUV)
  • Lx ≥ 10²⁹ ergs/s

Summary CVs in GCs

• Few of CVs per cluster

• X-ray biased sample:

  • Lx > 10²⁹ergs/s

• Dearth of DNe:

  • Only 17 confirmed

• Core-collapsed:

  • Bimodal population

• Non core-collapsed:

  • 1 faint population

• Period distribution?

  • 16 known periods

All Magnetics ?

• 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

• Closest Core Collapse
• Second Closest
  • 2.4 kpc
  • 15 CV candidates
  • 2 Pulsars

Preliminary Results

NGC 6397

We haven't found new

X-ray faint CVs

Spoiler Alert!

Other Binaries

Credits: NASA/Rivera Sandoval

Main et al 2018 (Nature)

Redback 'spider' Pulsar

Redback  Pulsar

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
  • Confirmed by Zhang et al. (2022)

Magnetic He WD Candidate

• V_rad > 150 km/s (MUSE)
• Not Detected in X-rays
  • Lx < 10²⁸ ergs/s
• Roche-lobe filling stripped star?
  • M~ 2 x 10^-4 ☉

• 18.4 hours 

Rotational Period

ESO/L. Calçada

Please talk to me about:

(Things I want to learn more about)

• Compact Binaries/Binary Evolution:

  • White Dwarfs Binaries and LISA
  • Common Envelope
  • Stripped Stars (e.g. sdB, WR, ...)
  • Products  of Binary Evolution (e.g. Barium Stars, R CrB, ELMs ...)
  • Halo vs Thick Disk Population (Gaia):
• Star Clusters (GCs     ):
  • LISA background
  • WD binaries in GCs (Binary Evolution)
• Time-Series Analysis:
  • Methods:
    • Gaussian Process
      • Flickering/QPOs/Magnetism in Symbiotics
    • Classification (unsupervised):
      • Dynamic time warping/The information bottleneck method
      • Where are all the AM CVns?

Also interested in:

• TESS:
  • Transients
  • Crowding
  • Symbiotics
• Halo vs Thick Disk:
  • Halo CVs
  • Halo AM CVns?

Data from Peters (2008)

Blue Variables

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...

Where are all the CVs?

Preliminary Results

M 92

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

Preliminary Results

NGC 6397

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

He WD Candidate

 Pichardo Marcano et al. (2023)

HACKS CMD

 Data: Libralato et al. (2022)

Also interested in:

• Magnetic White Dwarfs:
  • A Magnetic Extremely Low-Mass WD in a Globular Cluster?
  • Magnetic WDs in Symbiotics from TESS:
    • Spin-up?

Data from Peters (2008)

• 18.4 hours 

• Halo vs Thick Disk:
  • Halo CVs:
    • Not Period Bouncers
  • Halo AM CVns

Pichardo Marcano et al. (2023)

Z And

28 min to 26.7 min in 20 Yr

He WD Candidate

Tracks from Althaus et al. (2009)

0.16 M☉

 0.22  M⊙

0.52 M⊙

• 18.4 hours 

He WD Candidate

Magnetic He WD Candidate

• Binary: Vrad > 150 km/s (MUSE)
• Not Detected in X-rays
  • Lx < 10²⁸ ergs/s
• Not an Roche-lobe filling stripped star
  • M~ 2 x 10^-4 ☉

• 18.4 hours 

Rotational Period

ESO/L. Calçada

He WD Candidate

 Pichardo Marcano et al. (2023)

MUSE spectrum

Data from Husser et al. (2016), Kamman et al. (2016)

• 5.3 hours 

Variable and No Hα Excess

• Not Detected in X-rays
• 0.2 Δmag in F336W
  
• No Hα in Excess
  
• Periodicity

  • 5.3 hours 

Variable WD Candidate

 Pichardo Marcano et al. (in prep.)

HUGS CMD

Data: Piotto et al.(2015)/ Nardiello et al. (2018)

Variable WD Candidate

 Pichardo Marcano et al. (in prep.)

HUGS CMD

Data: Piotto et al.(2015)/ Nardiello et al. (2018)

AM CVn Donors

van Roestel et al. 2022

q = M2/M1

0.0125 < q < 0.18

M2 = Donor

AM CVn Donors

Coleman et al. 2018

0.0125 < q < 0.18

<R_d> ~10¹⁰cm

q = M2/M1

AM CVn Donors

Coleman et al. 2018

0.0125 < q < 0.18

<R_d> ~10¹⁰cm

q = M2/M1

Mass-transfer rates vs orbital period

Mass-transfer rates vs orbital period

Magnetic He WD Candidate

 Pichardo Marcano et al. (2023)

• 18.4 hours

• 0.16 M☉

• 0.24 R☉
• 0.11 Gyr
• Teff 7586 K
• log g = 4.9

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

Compact Binaries Surveys

2- SCOVaS: Survey for Compact Objects and Variables

Pichardo Marcano et al. (2021a)

Pichardo Marcano et al. (2023)

   Pichardo Marcano et al. (in prep.)

1- TACOS: TESS AM CVn Outbursts Survey

Pichardo Marcano et al. (2021b)

Caltech

NASA

• Color Evolution

PTF1 J0719+4858

Pichardo Marcano et al. (2021)

ZTF

SO

NO

SO

NO

rebrightening

rebrightening

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

SDSS J1043+5632

ZTF

TESS

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

SDSS J1043+5632

ZTF

TESS

PTF1 J0719+4858:

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

Color Evolution

Pichardo Marcano et al. (2021)

Accreting White Dwarf Binaries

Cataclysmic Variables

AM CVn

• Main Sequence Star
• P_orb ~ 80 min - 10 hours
• Outbursts:
  • 2-20 days
  • Disk instability model+ (DIM)
• >1000 in the galactic field
• Predicted large # in old Star Clusters

• White Dwarf/Helium Star
• P_orb ~ 5 - 70 min
• Outburts:
  • weeks?
  • DIM?
• ~70 in the galactic field

Mark A. Garlick

Caltech

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)

Color Evolution

PTF1 J0719+4858

SDSS J113732+405458

 Enhanced mass transfer

• Similar to Dwarf Novae

  • Hameury et al. (2020)

• Similar SDSS J1411+4812
  • Rivera Sandoval et al. (2021)
• Compare to SDSS 1137/SDSS 0807
  • Rivera Sandoval et al. (2021)

Pichardo Marcano et al. (2021)

Rivera Sandoval et al. (2021)

AM CVns

•  Helium Rich and Know to go into outburts

Normal Outbursts

V803 Cen

• WZ Sge like ?
  • Precursors
  • EMT (Hameury+'20)
  • Massive WD?

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

AM Canum Venaticorum AM CVn

• White dwarf + White dwarf

• White dwarf + He Star

• Orbital Period: 5-70 minutes

• Rare: 70 Galactic field

Caltech

• P_orb 20 to ~ 60 minutes (?)

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

• Disk instability model (DIM)

  •  Constant Mass transfer rate

  • Tidal-thermal disk instability model

    • SO: Superhumps (periodic brightness variation )

Outbursting Systems

AM CVns

•  Helium Rich and (some) known to go into outbursts

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/SDSS 0807
  • Rivera Sandoval et al. (2021)

Pichardo Marcano et al. (2021)

Type of Super Outbursts

Osaki et al. (2005)

High Mass Ratio

DIM

Cataclysmic Variables

• Evolution Superhump

Pichardo Marcano et al. (2021)

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

Caltech

• Porb 20 to ~ 60 minutes (?)

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

• Disk instability model (DIM)

  •  Constant Mass transfer rate

  • Tidal-thermal disk instability model

    • SO: Superhumps (periodic brightness variation )

Outbursting Systems

Place Constraints

Constraint Empirical Relationships

1. T_rec ∝ P_orb^7.35
2. T_dur ∝ P_orb^4.54
3. Δ mag ∝ P_orb
4. Ground-Based:
   1. PTF/CRTS
   2. ZTF
   3. LINEAR

Levitan et al. 2015

See also Duffy et al. 2021

1. T_rec ∝ P_orb^7.35
2. T_dur ∝ P_orb^4.54
3. Δ mag ∝ P_orb
4. Ground-Based:
   1. PTF/CRTS
   2. ZTF
   3. LINEAR

Levitan et al. 2015

See also Duffy et al. 2021

Need detailed short-term variability

Constraint Empirical Relationships

Long-term monitoring

Pichardo Marcano et al. (2021)

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

Type of Super Outbursts

Osaki et al. (2005)

High Mass Ratio

DIM

Cataclysmic Variables

Pichardo Marcano et al. (2021)

See also Duffy et al. (2021)