A Chandra Search for Coronal X Rays from the Cool White Dwarf GD 356

Abstract

We report observations with the Chandra X-ray Observatory of the single, cool, magnetic white dwarf GD 356. For consistent comparison with other X-ray observations of single white dwarfs, we also re-analyzed archival ROSAT data for GD 356 (GJ 1205), G 99-47 (GR 290 = V1201 Ori), GD 90, G 195-19 (EG250 = GJ 339.1), and WD 2316+123 and archival Chandra data for LHS 1038 (GJ 1004) and GD 358 (V777 Her). Our Chandra observation detected no X rays from GD 356, setting the most restrictive upper limit to the X-ray luminosity from any cool white dwarf -- L_{X} < 6.0 x 10^{25} ergs/s, at 99.7% confidence, for a 1-keV thermal-bremsstrahlung spectrum. The corresponding limit to the electron density is n_{0} < 4.4 x 10^{11} cm^{-3}. Our re-analysis of the archival data confirmed the non-detections reported by the original investigators. We discuss the implications of our and prior observations on models for coronal emission from white dwarfs. For magnetic white dwarfs, we emphasize the more stringent constraints imposed by cyclotron radiation. In addition, we describe (in an appendix) a statistical methodology for detecting a source and for constraining the strength of a source, which applies even when the number of source or background events is small.

27 pages, 4 figures, submitted to the Astrophysical Journal

References in corpus (2)

• The USNO-B Catalog
• Prospects for Measuring Differential Rotation in White Dwarfs Through Asteroseismology

Cited by in corpus (79)

• The Chandra Deep Field-South Survey: 4 Ms Source Catalogs
• Innovations in the Analysis of Chandra-ACIS Observations
• A Catalog of X-ray Point Sources from Two Megaseconds of Chandra Observations of the Galactic Center
• Magnetic fields in isolated and interacting white dwarfs
• Azimuthally Resolved X-Ray Spectroscopy to the Edge of the Perseus Cluster
• The X-ray properties of $z>6$ quasars: no evident evolution of accretion physics in the first Gyr of the Universe
• Buried AGNs in Advanced Mergers:Mid-infrared color selection as a dual AGN finder
• NuSTAR Reveals Extreme Absorption in z < 0.5 Type 2 Quasars
• On Computing Upper Limits to Source Intensities
• The Chandra Deep Protocluster Survey: Point-Source Catalogs for a 400 ks Observation of the z = 3.09 Protocluster in SSA22
• NuSTAR Observations of Heavily Obscured Quasars at z ~ 0.5
• Heavy X-ray obscuration in the most-luminous galaxies discovered by WISE
• NuSTAR Hard X-ray Survey of the Galactic Center Region II: X-ray Point Sources
• The most luminous blue quasars at $3.0<z<3.3$. I. A tale of two X-ray populations
• The $L_{\mathrm{x}}$-$L_{\mathrm{uv}}$-$L_{\mathrm{radio}}$ relation and corona-disk-jet connection in optically selected radio-loud quasars
• Variability Selected Low-Luminosity Active Galactic Nuclei in the 4 Ms Chandra Deep Field-South
• Six millisecond pulsars detected by the Fermi Large Area Telescope and the radio/gamma-ray connection of millisecond pulsars
• Neutron star radius measurement from the ultraviolet and soft X-ray thermal emission of PSR J0437-4715
• An Ultra-deep Chandra Catalog of X-ray Point Sources in the Galactic Center Star Cluster
• X-ray Emission from the Binary Central Stars of the Planetary Nebulae HFG 1, DS 1, and LoTr 5
• The cold neutron star in the soft X-ray transient 1H 1905+000
• Stellar Clusters in the NGC 6334 Star Forming Complex
• X-ray Bright Active Galactic Nuclei in Massive Galaxy Clusters I: Number Counts and Spatial Distribution
• HYPerluminous quasars at the Epoch of ReionizatION (HYPERION). A new regime for the X-ray nuclear properties of the first quasars
• Dominance of Magnetic Cataclysmic Variables in the Resolved Galactic Ridge X-ray Emission of the Limiting Window
• Storm in a Teacup: X-ray view of an obscured quasar and superbubble
• The MAVERIC Survey: Chandra/ACIS Catalog of Faint X-ray sources in 38 Galactic globular clusters
• Discovery of the first heavily obscured QSO candidate at $z>6$ in a close galaxy pair
• A Chandra Look at the X-ray Faint Millisecond Pulsars in the Globular Cluster NGC 6752
• New X-ray observations of the Geminga pulsar wind nebula
• X-ray Observations of a $z\sim 6.2$ Quasar/Galaxy Merger
• Enhanced X-ray Emission from the Most Radio-Powerful Quasar in the Universe's First Billion Years
• The Massive Star Forming Region Cygnus OB2. I. Chandra catalogue of association members
• The Massive Star-Forming Regions Omnibus X-Ray Catalog, Second Installment
• The Massive Star-Forming Regions Omnibus X-Ray Catalog, Third Installment
• Single magnetic white dwarfs with Balmer emission lines: A small class with consistent physical characteristics as possible signposts for close-in planetary companions
• Chandra reveals a luminous Compton-thick QSO powering a $Ly\alpha$ blob in a $z=4$ starbursting protocluster
• Multi-wavelength observations of SDSS J105621.45+313822.1, a broad-line, low-metallicity AGN
• The Chandra Local Volume Survey I: The X-ray Point Source Populations of NGC 55, NGC 2403, and NGC 4214
• X-ray properties of dust-obscured galaxies with broad optical/UV emission lines
• Chandra and Magellan/FIRE follow-up observations of PSO167-13: an X-ray weak QSO at $z=6.515$
• Linking Stellar Coronal Activity and Rotation at 500 Myr: A Deep Chandra Observation of M37
• Explore the Axion Dark Matter through the Radio Signals from Magnetic White Dwarf Stars
• NuSTAR and Keck Observations of Heavily Obscured Quasars Selected by WISE
• A test of the planet-star unipolar inductor for magnetic white dwarfs
• Detecting Axion Dark Matter through the Radio Signal from Omega Centauri
• Nowhere to Hide: Radio-faint AGN in the GOODS-N field. II. Multi-wavelength AGN selection techniques and host galaxy properties
• The NuSTAR Hard X-ray Survey of the Norma Arm Region
• Exploring the Mass Segregation Effect of X-ray Sources in Globular Clusters: The Case of 47 Tucanae
• Deep XMM-Newton Observations of an X-ray Weak, Broad Absorption Line Quasar at $z=6.5$
• Fast SMBH growth in the SPT2349--56 protocluster at $z=4.3$
• The Norma Arm Region Chandra Survey: X-ray Populations in the Spiral Arms
• X-ray emission from a rapidly accreting narrow-line Seyfert 1 galaxy at z=6.56
• Disentangling Overlapping Astronomical Sources using Spatial and Spectral Information
• The X-ray spectral and variability properties of typical radio-loud quasars
• Populations of super-soft X-ray sources in galaxies of different morphological types
• Chasing the Identification of ASCA Galactic Objects (ChIcAGO) - An X-ray Survey of Unidentified Sources in the Galactic Plane I: Source Sample and Initial Results
• Does GD 356 have a Terrestrial Planetary Companion?
• Determining X-Ray Source Intensity and Confidence Bounds in Crowded Fields
• The SRG/eROSITA All-Sky Survey: X-ray beacons at late cosmic dawn
• The environmental dependence of X-ray AGN activity at $z\sim 0.4$
• The SWIFT AGN and Cluster Survey I: Number Counts of AGN and Galaxy Clusters
• X-ray photolysis of CH${}_3$COCH${}_3$ ice: Implications for the radiation effects of compact objects towards astrophysical ices
• GA-NIFS: The highly overdense system BR1202-0725 at z $\sim$ 4.7. A double AGN with fast outflows plus eight companion galaxies
• Exploring the Mass Segregation Effect of X-ray Sources in Globular Clusters. II. The Case of Terzan 5
• No evidence for an Eddington-ratio dependence of X-ray weakness in BALQSOs
• A big red dot at cosmic noon
• Listening for Dark Photon Radio from the Galactic Centre
• Exploring the Mass Segregation Effect of X-ray Sources in Globular Clusters. III. Signs of Binary Disruption in M28
• An X-ray fading, UV brightening QSO at $z\approx 6$
• Chandra Detection of Intra-cluster X-ray Sources in Fornax
• Imaging Analysis of the Hard X-ray Telescope ProtoEXIST2 and New Techniques for High Resolution Coded Aperture Telescopes
• Hard X-ray Emission Associated with White Dwarfs. IV. Signs of Accretion from Sub-stellar Companions
• Searching for high-energy gamma-ray counterparts to Gravitational Wave sources with Fermi-LAT: a needle in a haystack
• Atmospheric heating and magnetism driven by ${}^{22}$Ne distillation in isolated white dwarfs
• Discovery of Dipolar Chromospheres in Two White Dwarfs
• Intervening nuclear obscuration changing the X-ray look of the $z\approx 6$ QSO CFHQS J164121+375520
• The Decline and Fall of ROME. V. A Preliminary Search for Star-Disrupted Planet Interactions and Coronal Activity at 5 GHz Among White Dwarfs within 25 pc
• Identification of high-energy astrophysical point sources via hierarchical Bayesian nonparametric clustering