We present the results of an archival XMM-Newton study of the bright X-ray point sources (LX>10^38^ergs/s) in 32 nearby galaxies. From our list of approximately 100 point sources, we attempt to determine if there is a low-state counterpart to the ultraluminous X-ray (ULX) population, searching for a soft-hard state dichotomy similar to that known for Galactic X-ray binaries and testing the specific predictions of the intermediate-mass black hole (IMBH) hypothesis. To this end, we searched for low-state objects, which we defined as objects within our sample that had a spectrum well fitted by a simple absorbed power law, and high-state objects, which we defined as objects better fitted by a combined blackbody and a power law.
We search for ultra luminous X-ray source (ULXs) radio counterparts located in nearby galaxies in order to constrain their physical nature. Our work is based on a systematic cross-identification of the most recent and extensive available ULX catalogues and archival radio data. A catalogue of 70 positional coincidences is reported. Most of them are located within the galaxy nucleus. Among them, we find 11 new cases of non-nuclear ULX sources with possibly associated radio emission.
We present a mid-infrared (IR) sample study of nearby ultraluminous X-ray sources (ULXs) using multiepoch observations with the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. Spitzer/IRAC observations taken after 2014 were obtained as part of the Spitzer Infrared Intensive Transients Survey. Our sample includes 96 ULXs located within 10 Mpc. Of the 96 ULXs, 12 have candidate counterparts consistent with absolute mid-IR magnitudes of supergiants, and 16 counterparts exceeded the mid-IR brightness of single supergiants and are thus more consistent with star clusters or non-ULX background active galactic nuclei. The supergiant candidate counterparts exhibit a bimodal color distribution in a Spitzer/IRAC color-magnitude diagram, where "red" and "'blue" ULXs fall in IRAC colors [3.6]-[4.5]~0.7 and [3.6]-[4.5]~0.0, respectively. The mid-IR colors and absolute magnitudes of four "red" and five "blue" ULXs are consistent with those of supergiant B[e] (sgB[e]) and red supergiant (RSG) stars, respectively. Although "blue," RSG-like mid-IR ULX counterparts likely host RSG mass donors; we propose that "red" counterparts are ULXs exhibiting the "B[e] phenomenon" rather than hosts of sgB[e] mass donors. We show that the mid-IR excess from the "red" ULXs is likely due to thermal emission from circumstellar or circumbinary dust. Using dust as a probe for total mass, we estimate mass-loss rates of dM/dt~1x10^-4^M_{sun}_/yr in dust-forming outflows of red ULXs. Based on the transient mid-IR behavior and its relatively flat spectral index, {alpha}=-0.19+/-0.1, we suggest that the mid-IR emission from Holmberg IX X-1 originates from a variable jet.
Ulysses Jupiter Encounter Cospin Anisotropy Telescope (AT) Flux Data
Collection
Short Name:
ULY-COSPIN-AT
Date:
04 Mar 2024 19:08:32
Publisher:
Planetary Data System
Description:
This collection contains data submitted to the Planetary Data System
(PDS) by the Ulysses COSPIN investigators, for the Ulysses Jupiter
Encounter, 1992-01-25 to 1992-02-17 (days 25-48 inclusive).
Ulysses Jupiter Encounter Cospin High Energy Telescope (HET) Flux Data
Collection
Short Name:
ULY-COSPIN-HET
Date:
04 Mar 2024 19:09:00
Publisher:
Planetary Data System
Description:
This file contains data submitted to the Planetary Data System (PDS)
by the Ulysses COSPIN investigators, for the Ulysses Jupiter
Encounter, 1992-01-25 to 1992-02-17 (days 25-48 inclusive). All data
on this volume are from the High Energy Telescope (HET) detector.
Ulysses Jupiter Encounter Cospin High Flux Telescope (HFT) Flux Data
Collection
Short Name:
ULY-COSPIN-HFT
Date:
04 Mar 2024 19:10:16
Publisher:
Planetary Data System
Description:
This file contains data submitted to the Planetary Data System (PDS)
by the Ulysses COSPIN investigators, for the Ulysses Jupiter
Encounter, 1992-01-25 to 1992-02-18 (days 25-48 inclusive). All data
on this volume are from the High Flux Telescope (HFT) detector.
Ulysses Jupiter Encounter Cospin Kiel Electron Telescope (KET)
Intensity Data Collection
Short Name:
ULY-COSPIN-KET-I
Date:
04 Mar 2024 19:10:39
Publisher:
Planetary Data System
Description:
This file contains data submitted to the Planetary Data System (PDS)
by the Ulysses COSPIN investigators, for the Ulysses Jupiter
Encounter, 1992-01-24 to 1992-02-17 (days 25-48 inclusive). All data
on this volume are from the Kiel Electron Telescope (KET) detector.
Ulysses Jupiter Encounter Cospin Kiel Electron Telescope (KET) Raw
Data Collection
Short Name:
ULY-COSPIN-KET-R
Date:
04 Mar 2024 19:11:05
Publisher:
Planetary Data System
Description:
This file contains data submitted to the Planetary Data System (PDS)
by the Ulysses COSPIN investigators, for the Ulysses Jupiter
Encounter, 1992-01-24 to 1992-02-17 (days 25-48 inclusive). All data
on this volume are from the Kiel Electron Telescope (KET) detector.
Ulysses Jupiter Encounter Cospin Low Energy Telescope (LET) Flux Data
Collection
Short Name:
ULY-COSPIN-LET
Date:
04 Mar 2024 19:15:39
Publisher:
Planetary Data System
Description:
This file contains data submitted to the Planetary Data System (PDS)
by the Ulysses COSPIN investigators, for the Ulysses Jupiter
Encounter, 1992-01-25 to 1992-02-17 (days 25-48 inclusive). All data
on this volume are from the Low Energy Telescope (LET) detector.
We present interplanetary network localization information for 218 gamma-ray bursts in the third BATSE catalog obtained by analyzing the arrival times of these bursts with the Ulysses and Compton Gamma Ray Observatory spacecraft. For any given burst observed by these two spacecraft, arrival time analysis (or "triangulation") results in an annulus of possible arrival directions whose half-width varies between 7'' and 32', depending on the intensity and time history of the burst and the distance of the Ulysses spacecraft from Earth. This annulus generally intersects the BATSE error circle, which results in an average reduction of a factor of 30 of the error box area.
