Discovery of a 3.5 keV line in the Galactic Center and a Critical Look at the Origin of the Line Across Astronomical Targets

Abstract

We examine the claimed excess X-ray line emission near 3.5 keV including both a new analysis of XMM-Newton observations of the Milky Way center and a reanalysis of the data on M~31 and clusters. In no case do we find conclusive evidence for an excess. In the case of the Galactic center we show that known plasma lines, including in particular K XVIII lines at 3.48 and 3.52 keV, provide a satisfactory fit to the XMM data. We estimate the expected flux of the K XVIII lines and find that the measured line flux falls squarely within the predicted range based on the brightness of other well-measured lines in the energy range of interest and on detailed multi-temperature plasma models. We then re-assess the evidence for excess emission from clusters of galaxies, allowing for systematic uncertainty in the expected flux from known plasma lines and additional uncertainty due to potential variation in the abundances of different elements. We find that no conclusive excess line emission can be advocated when considering systematic uncertainties in Perseus or in other clusters. We also re-analyze the XMM data for M~31 and find no statistically significant line emission near 3.5 keV to a level greater than one sigma. Finally, we analyze the Tycho supernova remnant, which shows similar plasma features to the sources above, but does not host any significant dark matter. We detect a 3.55 keV line from Tycho, which points to possible systematic effects in the flux determination of weak lines, or to relative elemental abundances vastly different from theoretical expectations.

arXiv commentv.2: significant additions and revisions, including new studies of the Tycho SNR, multi-temperature plasma models, systematic effects; conclusions substantially unchanged from v.1; accepted for publication in Monthly Notices of the Royal Astronomical Society

References in corpus (54)

• Collisional Plasma Models with APEC/APED: Emission Line Diagnostics of Hydrogen-like and Helium-like Ions
• Nucleosynthesis in Chandrasekhar Mass Models for Type Ia Supernovae and Constraints on Progenitor Systems and Burning-Front Propagation
• SparsePak: A Formatted Fiber Field Unit for The WIYN Telescope Bench Spectrograph. I. Design, Construction, and Calibration
• Detection of An Unidentified Emission Line in the Stacked X-ray spectrum of Galaxy Clusters
• The role of sterile neutrinos in cosmology and astrophysics
• Three-dimensional delayed-detonation models with nucleosynthesis for Type Ia supernovae
• A Catalog of Galaxy Clusters Observed by XMM-Newton
• Nucleosynthesis in multi-dimensional SNIa explosions
• Discrete sources as the origin of the Galactic X-ray ridge emission
• Diffuse X-ray Emission in a Deep Chandra Image of the Galactic Center
• Nucleosynthesis in Two-Dimensional Delayed Detonation Models of Type Ia Supernova Explosions
• The Poker Face of the Majoron Dark Matter Model: LUX to keV Line
• Chandra-HETGS Observations of the Brightest Flare Seen from Sgr A*
• Constraints on 3.55 keV line emission from stacked observations of dwarf spheroidal galaxies
• Resonantly-Produced 7 keV Sterile Neutrino Dark Matter Models and the Properties of Milky Way Satellites
• The Quest for an Intermediate-Scale Accidental Axion and Further ALPs
• A 3.55 keV hint for decaying axion-like particle dark matter
• Expansion Velocity of Ejecta in Tycho's Supernova Remnant Measured by Doppler Broadened X-ray Line Emission
• The Interplay between Star Formation and the Nuclear Environment of our Galaxy: Deep X-ray Observations of the Galactic Center Arches and Quintuplet Clusters
• The 7 keV axion dark matter and the X-ray line signal
• A 3.55 keV Photon Line and its Morphology from a 3.55 keV ALP Line
• The K-shell Line Distribution of Heavy Elements along the Galactic Plane Observed with Suzaku
• A Dark Matter Progenitor: Light Vector Boson Decay into (Sterile) Neutrinos
• X-ray line signal from 7 keV axino dark matter decay
• Unresolved emission and ionized gas in the bulge of M31
• X-ray line signal from decaying axino warm dark matter
• Dark Matter in the minimal Inverse Seesaw mechanism
• 7 keV sterile neutrino dark matter from split flavor mechanism
• Generating X-ray lines from annihilating dark matter
• X-ray Lines from Dark Matter: The Good, The Bad, and The Unlikely
• 3.5 keV X-rays as the "21 cm line" of dark atoms, and a link to light sterile neutrinos
• 3.55 keV photon lines from axion to photon conversion in the Milky Way and M31
• X-ray lines from R-parity violating decays of keV sparticles
• XMM-Newton observations of Sagittarius A East
• A Candidate Neutron Star Associated with Galactic Center Supernova Remnant Sagittarius A East
• 3.5 keV x-ray line from decaying gravitino dark matter
• Axino dark matter in light of an anomalous X-ray line
• keV Photon Emission from Light Nonthermal Dark Matter
• 3.55 keV X-ray Line Signal from Excited Dark Matter in Radiative Neutrino Model
• A Dynamical Framework for KeV Dirac Neutrino Warm Dark Matter
• Magnetic dark matter for the X-ray line at 3.55 keV
• Suzaku Spectroscopy Study of Hard X-Ray Emission in the Arches Cluster
• The 3.5 keV X-ray line signal from decaying moduli with low cutoff scale
• XMM-Newton observations of the Galactic Centre Region - I: The distribution of low-luminosity X-ray sources
• Cluster X-ray line at $3.5\mathrm{keV}$ from axion-like dark matter
• Neutrino masses, leptogenesis, and sterile neutrino dark matter
• SUSY in the sky or a keV signature of sub-GeV gravitino dark matter
• X-ray Line from the Dark Transition Electric Dipole
• Effective field theory and keV lines from dark matter
• XMM-Newton and Chandra Observations of the Central Region of M31
• X-ray spectroscopy of the hot has in the M31 bulge
• 3.5 keV X-ray line and R-Parity Conserving Supersymmetry
• XMM-Newton observations of the Galactic Centre Region - II: The soft thermal emission
• Three sterile neutrinos in E6

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