Search Publications
Spectroscopic Indication of a Centi-parsec Supermassive Black Hole Binary in the Galactic Center of NGC 5548
Ho, Luis C.; Zhang, Zhi-Xiang; Du, Pu +8 more
As a natural consequence of cosmological hierarchical structure formation, sub-parsec supermassive black hole binaries (SMBHBs) should be common in galaxies but thus far have eluded spectroscopic identification. Based on four decades of optical spectroscopic monitoring, we report that the nucleus of NGC 5548, a nearby Seyfert galaxy long suspected…
KMOS3D: Dynamical Constraints on the Mass Budget in Early Star-forming Disks
Übler, Hannah; van Dokkum, Pieter G.; Bender, Ralf +26 more
We exploit deep integral-field spectroscopic observations with KMOS/Very Large Telescope of 240 star-forming disks at 0.6\lt z\lt 2.6 to dynamically constrain their mass budget. Our sample consists of massive (≳ {10}9.8 {M}⊙ ) galaxies with sizes {R}e≳ 2 {kpc}. By contrasting the observed velocity and dispersion p…
Slipping Magnetic Reconnection, Chromospheric Evaporation, Implosion, and Precursors in the 2014 September 10 X1.6-Class Solar Flare
Polito, Vanessa; Del Zanna, Giulio; Aulanier, Guillaume +7 more
We investigate the occurrence of slipping magnetic reconnection, chromospheric evaporation, and coronal loop dynamics in the 2014 September 10 X-class flare. Slipping reconnection is found to be present throughout the flare from its early phase. Flare loops are seen to slip in opposite directions toward both ends of the ribbons. Velocities of 20-4…
A Coherent Study of Emission Lines from Broadband Photometry: Specific Star Formation Rates and [O III]/Hβ Ratio at 3 > z > 6
Ilbert, O.; Silverman, J. D.; Salvato, M. +14 more
We measure the Hα and [O III] emission line properties as well as specific star formation rates (sSFRs) of spectroscopically confirmed 3 < z < 6 galaxies in COSMOS from their observed colors versus redshift evolution. Our model describes consistently the ensemble of galaxies including intrinsic properties (age, metallicity, star formation hi…
"Refsdal" Meets Popper: Comparing Predictions of the Re-appearance of the Multiply Imaged Supernova Behind MACSJ1149.5+2223
Sharon, K.; Diego, J. M.; Zitrin, A. +25 more
Supernova “Refsdal,” multiply imaged by cluster MACS1149.5+2223, represents a rare opportunity to make a true blind test of model predictions in extragalactic astronomy, on a timescale that is short compared to a human lifetime. In order to take advantage of this event, we produced seven gravitational lens models with five independent methods, bas…
INTEGRAL Upper Limits on Gamma-Ray Emission Associated with the Gravitational Wave Event GW150914
Hanlon, L.; Mereghetti, S.; von Kienlin, A. +14 more
Using observations of the INTErnational Gamma-Ray Astrophysics Laboratory (INTEGRAL), we place upper limits on the gamma-ray and hard X-ray prompt emission associated with the gravitational wave event GW150914, which was discovered by the LIGO/Virgo Collaboration. The omnidirectional view of the INTEGRAL/SPI-ACS has allowed us to constrain the fra…
Are IRIS Bombs Connected to Ellerman Bombs?
He, Jiansen; Tian, Hui; Xu, Zhi +1 more
Recent observations by the Interface Region Imaging Spectrograph (IRIS) have revealed pockets of hot gas (∼2-8 × 104 K) potentially resulting from magnetic reconnection in the partially ionized lower solar atmosphere (IRIS bombs; IBs). Using joint observations between IRIS and the Chinese New Vacuum Solar Telescope, we have identified 1…
Do the Most Massive Black Holes at z = 2 Grow via Major Mergers?
Jahnke, K.; Silverman, J. D.; Schulze, A. +11 more
The most frequently proposed model for the origin of quasars holds that the high accretion rates seen in luminous active galactic nuclei (AGN) are primarily triggered during major mergers between gas-rich galaxies. While plausible for decades, this model has only begun to be tested with statistical rigor in the past few years. Here, we report on a…
M31N 2008-12a - The Remarkable Recurrent Nova in M31: Panchromatic Observations of the 2015 Eruption.
Ness, J. -U.; Boumis, P.; Henze, M. +52 more
The Andromeda Galaxy recurrent nova M31N 2008-12a had been observed in eruption 10 times, including yearly eruptions from 2008 to 2014. With a measured recurrence period of {P}{rec}=351+/- 13 days (we believe the true value to be half of this) and a white dwarf very close to the Chandrasekhar limit, M31N 2008-12a has become the leading …
The Story of Supernova “Refsdal” Told by Muse
Treu, T.; Grillo, C.; Balestra, I. +10 more
We present Multi Unit Spectroscopic Explorer (MUSE) observations in the core of the Hubble Frontier Fields (HFF) galaxy cluster MACS J1149.5+2223, where the first magnified and spatially resolved multiple images of supernova (SN) “Refsdal” at redshift 1.489 were detected. Thanks to a Director's Discretionary Time program with the Very Large Telesc…