A Systematic Search of Zwicky Transient Facility Data for Ultracompact Binary LISA-detectable Gravitational-wave Sources

Burdge, Kevin B.; Prince, Thomas A.; Fuller, Jim; Kaplan, David L.; Marsh, T. R.; Tremblay, Pier-Emmanuel; Zhuang, Zhuyun; Bellm, Eric C.; Caiazzo, Ilaria; Coughlin, M. W.; Dhillon, V.; Gaensicke, B. T.; Rodríguez‐Gil, P.; Graham, M. J.; Hermes, J. J.; Kupfer, Thomas; Littlefair, S.; Mróz, P.; Phinney, E. S.; Roestel, Jan van; Yao, Yuhan; Dekany, Richard; Drake, A. J.; Duev, Dmitry A.; Hale, David; Feeney, Michael; Hélou, G.; Kaye, Stephen B.; Mahabal, A.; Masci, Frank J.; Riddle, Reed; Smith, Roger M.; Soumagnac, Maayane T.; Kulkarni, S. R.

doi:10.3847/1538-4357/abc261

Cited by 87 publications

(77 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Period Detection Our search for periodicity in massive white dwarfs was part of a broader search for periodic variability on and around the white dwarf cooling track with ZTF, which has already yielded several results, including finding numerous double white dwarf binaries 2,3,47 . The targets were selected using Pan-STARRS (PS1) source catalogue 32 , after imposing a photometric colour selection of (g−r) < 0.2 and (r−i) < 0.2.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

A highly magnetized and rapidly rotating white dwarf as small as the Moon

Caiazzo

Burdge

Fuller

et al. 2021

Nature

Self Cite

View full text Add to dashboard Cite

in binaries [1][2][3] . If the orbital period of the binary is short enough, energy losses from gravitational wave radiation can shrink the orbit until the two white dwarfs come into contact and merge 4 . Depending on the masses of the coalescing white dwarfs, the merger can lead to a supernova of type Ia, or it can give birth to a massive white dwarf 5 . In the latter case, the white dwarf remnant is expected to be highly magnetised 6,7 due to the strong dynamo that may arise during the merger, and rapidly rotating due to conservation of the orbital angular momentum of the binary 8 . Here we report the discovery of a white dwarf, ZTF J190132.9+145808.7, which presents all these properties, but to an extreme: a rotation period of 6.94 minutes, one of the shortest measured for an isolated white dwarf 9, 10 , a magnetic field ranging between 600 MG and 900 MG over its surface, one of the highest fields ever detected on a white dwarf 11 , and a stellar radius of 1810 km, slightly larger than the radius of the Moon. Such a small radius implies the star's mass is the closest ever detected to the white dwarf maximum mass, or Chandrasekhar mass 12 . In fact, as the white dwarf cools and its composition stratifies, it may become unstable and collapse due to electron capture, exploding into a thermonuclear supernova or collapsing into a neutron star. Neutron stars born in this fashion could account for ∼10% of their total population.The Zwicky Transient Facility [13][14][15] (ZTF) is a synoptic optical survey that uses the 48-inch Samuel Oschin Telescope of the Palomar Observatory to image the Northern sky on a regular basis.We discovered ZTF J190132.9+145808.7 (hereafter ZTF J1901+1458) during a search for fast variability in massive white dwarfs. To this end, we selected objects in a white dwarf catalogue 16 that lie below the main white dwarf cooling sequence in the Gaia 17 color-magnitude diagram (CMD,

show abstract

Section: Methodsmentioning

confidence: 99%

“…

…”

mentioning

confidence: 99%

A highly magnetized and rapidly rotating white dwarf as small as the Moon

Caiazzo

Burdge

Fuller

et al. 2021

Nature

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the DD scenario, this number will provide an independent probe of the rate of mergers of WD binaries. This will be particularly useful, as close WD binaries will be important gravitational-wave sources for LISA (Amaro-Seoane et al 2017; Burdge et al 2020).…”

Section: Introductionmentioning

confidence: 99%

Census of R Coronae Borealis Stars. I. Infrared Light Curves from Palomar Gattini IR

Karambelkar

Kasliwal

Tisserand

et al. 2021

ApJ

Self Cite

View full text Add to dashboard Cite

We are undertaking the first systematic infrared (IR) census of R Coronae Borealis (RCB) stars in the Milky Way, beginning with IR light curves from the Palomar Gattini IR (PGIR) survey. The PGIR is a 30 cm J-band telescope with a 25 deg 2 camera that is surveying 18,000 deg 2 of the northern sky (δ > −28°) at a cadence of 2 days. We present PGIR light curves for 922 RCB candidates selected from a mid-IR color-based catalog. Of these 922, 149 are promising RCB candidates, as they show pulsations or declines similar to RCB stars. The majority of the candidates that are not RCB stars are either long-period variables (LPVs) or RV Tauri stars. We identify IR color-based criteria to better distinguish between RCB stars and LPVs. As part of a pilot spectroscopic run, we obtain NIR spectra for 26 of the 149 promising candidates and spectroscopically confirm 11 new RCB stars. We detect strong He I λ10830 features in the spectra of all RCB stars, likely originating within high-velocity (200-400 km s −1 ) winds in their atmospheres. Nine of these RCB stars show 12 C 16 O and 12 C 18 O molecular absorption features, suggesting that they are formed through a white dwarf merger. We detect quasiperiodic pulsations in the light curves of five RCB stars. The periods range between 30 and 125 days and likely originate from the strange-mode instability in these stars. Our pilot run results motivate a dedicated IR spectroscopic campaign to classify all RCB candidates.Unified Astronomy Thesaurus concepts: R Coronae Borealis variable stars (1327); Hydrogen deficient stars (769); Near infrared astronomy (1093); Time domain astronomy (2109)

show abstract

“…The completeness of our method to find all AM CVn systems is limited by our search to objects that show outbursts of 1.5 magnitudes or more. While this selection method reduces the number of candidates by four orders of magnitude (Figure 1), it does mean that we will only find AM CVn systems that outburst in the period range of 22  P orb  50 m. To find the shorter and longer period AM CVn systems that do not show outbursts, other methods are needed (e.g., Burdge et al 2020;van Roestel 2021).…”

Section: Selection By Outburstsmentioning

confidence: 99%

“…Isogai et al (2019) also focused on outbursting CVs, but instead used high-cadence photometry to measure the superhump period (periodic variability due to an asymmetry in the disk shape) and classify a system as an AM CVn. Searching for short-period variability was also used to identify a new AM CVn system (e.g., Kupfer et al 2015;Green et al 2018b;Burdge et al 2020). Despite all these efforts, we are still missing a significant number of nearby AM CVn systems (see for example Figure 5 in Ramsay et al 2018).…”

Section: Introductionmentioning

confidence: 99%

A Systematic Search for Outbursting AM CVn Systems with the Zwicky Transient Facility

Roestel

Creter

Kupfer

et al. 2021

Self Cite

View full text Add to dashboard Cite

AM CVn systems are a rare type of accreting binary that consists of a white dwarf and a helium-rich, degenerate donor star. Using the Zwicky Transient Facility (ZTF), we searched for new AM CVn systems by focusing on blue, outbursting stars. We first selected outbursting stars using the ZTF alerts. We cross matched the candidates with Gaia and Pan-STARRS catalogs. The initial selection of candidates based on the Gaia BP-RP contains 1751 unknown objects. We used the Pan-STARRS g-r and r-i color in combination with the Gaia color to identify 59 strong AM CVn candidates. We obtained identification spectra of 35 sources, of which 18 are high-priority candidates, and discovered nine new AM CVn systems and one magnetic CV that shows only He-II lines. Using the outburst recurrence time, we estimate the orbital periods of the nine new AM CVn systems that are in the range of 29-50 minutes. We conclude that targeted follow up of blue, outbursting sources is an efficient method to find new AM CVn systems and we plan to follow up all candidates we identified to systematically study the population of outbursting AM CVn systems.

show abstract

A Systematic Search of Zwicky Transient Facility Data for Ultracompact Binary LISA-detectable Gravitational-wave Sources

Cited by 87 publications

References 90 publications

A highly magnetized and rapidly rotating white dwarf as small as the Moon

A highly magnetized and rapidly rotating white dwarf as small as the Moon

Census of R Coronae Borealis Stars. I. Infrared Light Curves from Palomar Gattini IR

A Systematic Search for Outbursting AM CVn Systems with the Zwicky Transient Facility

Contact Info

Product

Resources

About