Isotropic Luminosity Research Articles

Discovery of Water Maser Emission in Five AGNs and a Possible Correlation Between Water Maser and Nuclear 2–10 keV Luminosities

We report the discovery of water maser emission in five active galactic nuclei (AGNs) with the 100 m Green Bank Telescope (GBT). The positions of the newly discovered masers, measured with the VLA, are consistent with the optical positions of the host nuclei to within 1 � (0B3 radio and 1B3 optical) and most likely mark the locations of the embedded central engines. The spectra of three sources, 2MASX J08362280+3327383, NGC 6264, and UGC 09618 NED02, display the characteristic spectral signature of emission from an edge-on accretion disk with maximum orbitalvelocityof � 700, � 800,and � 1300kms � 1 ,respectively.WealsopresentaGBTspectrumofapreviouslyknown source, Mrk 0034, and interpret the narrow Doppler components reported here as indirect evidence that the emission originatesinanedge-onaccretiondiskwithorbitalvelocityof � 500kms � 1 .Weobtainedadetectionrateof 12%(5out of 41) among Seyfert 2 and LINER systems with 10,000 km s � 1 < vsys < 15;000 km s � 1 . For the 30 nuclear water masers with available hard X-ray data, we report a possible relationship between unabsorbed X-ray luminosity (2Y10 keV) and total isotropic water maser luminosity, L2� 10 / L 0:5� 0:1 H2O , consistent with the model proposed by Neufeld and Maloney, in which X-ray irradiation and heating of molecular accretion disk gas by the central engine excites the maser emission. Subject headingg galaxies: active — galaxies: individual (2MASX J08362280+3327383, NGC 6264, UGC 09618 NED02, IRAS 03355+0104, SBS 0927+493, Markarian 0034, NGC 3393, NGC 5495, VII Zw 073, IC 0184, AM 2158� 380 NED02) — galaxies: Seyfert — ISM: jets and outflows — ISM: molecules — masers

Variability of ultraluminous X-ray sources in the Cartwheel Ring

AbstractThe Cartwheel is one of the most outstanding examples of a dynamically perturbed galaxy where star formation is occurring inside the ring–like structure. In previous studies with Chandra, we detected 16 Ultra Luminous X-ray sources lying along the southern portion of the ring. Their Luminosity Function is consistent with them being in the high luminosity tail of the High Mass X-ray Binaries distribution, but with one exception: source N.10. This source, detected with Chandra at LX = 1 × 1041 erg s−1, is among the brightest non–nuclear sources ever seen in external galaxies. Recently, we have observed the Cartwheel with XMM-Newton in two epochs, six months apart. After having been at its brightest for at least 4 years, the source has dimmed by at least a factor of two between the two observations. This fact implies that the source is compact in nature. Given its extreme isotropic luminosity, there is the possibility that the source hosts an accreting intermediate–mass black hole. Other sources in the ring vary in flux between the different datasets. We discuss our findings in the context of ULX models.

A 62 Day X‐Ray Periodicity and an X‐Ray Flare from the Ultraluminous X‐Ray Source in M82

In 240 days of X-ray monitoring of M82, we have discovered an X-ray periodicity at 62.0 ? 2.5 days with a peak-to-peak amplitude corresponding to an isotropic luminosity of 2.4 ? 1040 ergs s-1 in M82 and an X-ray flare reaching a peak luminosity of 9.8 ? 1040 ergs s-1. The periodicity and flare likely originate from the ultraluminous X-ray source (ULX) in M82, which has been identified as a possible intermediate-mass black hole. We suggest that the 62 day modulation is due to orbital motion within an X-ray binary with a Roche lobe overflowing companion star, which would imply that the average density of the companion star is near 5 ? 10-5 g cm-3 and is therefore a giant or supergiant. Chandra observations just after the flare show an energy spectrum that is consistent with a power law with no evidence of a thermal component or line emission. Radio observations made with the VLA during the flare allow us to rule out a blazar identification for the source and place strong constraints on relativistically beamed models of the X-ray emission. The Chandra observations reveal that a second X-ray source reached a flux of 4.4 ? 10-12 ergs cm-2 s-1 in the 0.3-7 keV band, which is dramatically higher than any flux previously seen from this source and corresponds to an isotropic luminosity of 1.1 ? 1040 ergs s-1. This source is a second ultraluminous X-ray source in M82 and may give rise to the QPOs detected from the central region of M82.

Discovery of a tight correlation among the prompt emission properties of long gamma-ray bursts

We report the discovery of a correlation among three prompt emission properties of gamma-ray bursts (GRBs). These are the isotropic peak luminosity Liso, the peak energy (in νLν) of the time-integrated prompt emission spectrum Epk, and the ‘high signal’ time-scale T0.45, previously used to characterize the variability behaviour of bursts. In the rest frame of the source, the discovered correlation reads Liso∝E1.62pkT−0.490.45. We find other strong correlations, but at the cost of increasing the number of variables, involving the variability and the isotropic energy of the prompt emission. With respect to the other tight correlations found in GRBs (i.e. between the collimation corrected energy Eγ and Epk, the so-called Ghirlanda correlation, and the phenomenological correlation among the isotropic emitted energy Eiso,-Epk and the jet break time tbreak), the newly found correlation does not require any information from the afterglow phase of the bursts, nor any model-dependent assumption. In the popular scenario in which we are receiving beamed radiation originating in a fireball pointing at us, the discovered correlation preserves its form in the comoving frame. This helps to explain the small scatter of the correlation and underlines the role of the local brightness (i.e. the brightness of the visible fraction of the fireball surface). This correlation has been found with a relatively small number of objects and it is hard to establish if any selection bias affects it. Its connection with the prompt local brightness is promising, but a solid physical understanding is still to be found. Despite all that, we find that some properties of the correlation, which we discuss, support its true existence, and this has important implications for the GRB physics. Furthermore, it is possible to use such correlation as an accurate redshift estimator, and, more importantly, its tightness will allow us to use it as a tool to constrain the cosmological parameters.

Close Binary Interactions of Intermediate‐Mass Black Holes: Possible Ultraluminous X‐Ray Sources?

WhilemanyobservedultraluminousX-raysources(ULXs;LX � 10 39 ergss � 1 )couldbeextragalacticX-raybina- ries (XRBs) emitting close to the Eddington limit, the highest luminosity ULXs (LX > 3 ;10 39 ergs s � 1 ) exceed the isotropic Eddington luminosity for even high-stellar-mass-accreting black hole XRBs. It has been suggested that these highest luminosity ULXs may contain accreting intermediate-mass black hole (IMBH) binaries. We consider this hypothesis for dense, young (� 100 Myr) stellar clusters where we assume that a 50-500 Mcentral IMBH has formed through runaway growthof amassivestar.Wedevelopnumerical simulations ofsuch clusters' coresbycom- bining single and binary star evolutionary syntheses with a simple treatment of dynamical interactions. We model interactions of the IMBH with single and binary stars, as well as single-binary and binary-binary interactions, but not the formation of a cusp around the IMBH. The core density and velocity dispersion are assumed to be constant over 100 Myr. We investigate the succession of IMBH binary companions and the evolution of their orbital parameters to obtainestimates oftheincidenceofmasstransferphasesandpossibleULXactivityinvolvingtheIMBH.Wefindthat although it is common for the central black hole to acquire binary companions, there is a very low probability that these interacting binaries will become observable ULX sources. Subject headings: binaries: close — black hole physics — galaxies: star clusters — X-rays: binaries

Deceleration of a Relativistic, Photon‐rich Shell: End of Preacceleration, Damping of Magnetohydrodynamic Turbulence, and the Emission Mechanism of Gamma‐Ray Bursts

We consider the interaction of a relativistically moving shell, composed of thermal photons, a reversing magnetic field, and a small admixture of charged particles, with a dense Wolf-Rayet wind. A thin layer of Wolf-Rayet material is entrained at the head of this outflow; it cools and becomes Rayleigh-Taylor unstable, thereby providing an additional source of inertia and variability. The gamma rays streaming across the forward shock load the wind material with electron-positron pairs and push it to relativistic speeds close to the engine. This defines a characteristic radiative compactness at the point where the reverse shock has completed its passage back through the shell. We argue that the prompt gamma-ray emission is triggered by this external braking, at an optical depth ~1 to electron scattering. Torsional MHD waves, excited by the forced reconnection of the reversing magnetic field, carry a fluctuating current and are Landau damped at high frequencies on the parallel motion of the light charges. We show that the heated charges cool primilarly by inverse Compton radiation, which is beamed along the magnetic field. Thermal radiation that is advected out from the base of the jet cools the particles. The observed relation between peak energy and isotropic luminosity—both its amplitude and scaling—is reproduced if the blackbody seeds are generated in a relativistic jet core that is subject to Kelvin-Helmholtz instabilities with the Wolf-Rayet envelope. This relation is predicted to soften below an isotropic luminosity Liso ~ 3 × 1050 ergs s-1. Spectrally harder bursts will arise in outflows which encounter no dense stellar envelope. The duration of spikes in the inverse-Compton emission is narrower at higher frequencies, as observed. The transition from prompt gamma-ray emission to afterglow can be explained by the termination of the thermal X-ray seed and the onset of synchrotron-self-Compton emission.

Extragalactic H2O masers and X-ray absorbing column densities

Having conducted a search for the λ ~ 1.3 cm (22 GHz) water vapor line towards galaxies with nuclear activity, large nuclear column densities or high infrared luminosities, we present H2 O spectra for NGC 2273, UGC 5101, and NGC 3393 with isotropic luminosities of 7, 1500, and 400 . The H2 O maser in UGC 5101 is by far the most luminous yet found in an ultraluminous infrared galaxy. NGC 3393 reveals the classic spectrum of a “disk maser”, represented by three distinct groups of Doppler components. As in all other known cases except NGC 4258, the rotation velocity of the putative masing disk is well below 1000 km s-1 . Based on the literature and archive data, X-ray absorbing column densities are compiled for the 64 galaxies with reported maser sources beyond the Magellanic Clouds. For NGC 2782 and NGC 5728, we present Chandra archive data that indicate the presence of an active galactic nucleus in both galaxies. Modeling the hard nuclear X-ray emission, NGC 2782 is best fit by a high energy reflection spectrum with N H 1024 cm-2 . For NGC 5728, partial absorption with a power law spectrum indicates N H ~ 8 1023 cm-2 . The correlation between absorbing column and H2 O emission is analyzed. There is a striking difference between kilo- and megamasers with megamasers being associated with higher column densities. All kilomasers ( cm-2 . Among the H2 O megamasers, 50% arise from Compton-thick and 85% from heavily obscured (>1023 cm-2 ) active galactic nuclei. These values are not larger but consistent with those from samples of Seyfert 2 galaxies not selected on the basis of maser emission. The similarity in column densities can be explained by small deviations in position between maser spots and nuclear X-ray source and a high degree of clumpiness in the circumnuclear interstellar medium.

The Orbital Period of the Ultraluminous X-ray Source in M82

The ultraluminous x-ray source (ULX) in the galaxy M82 has been identified as a possible intermediate-mass black hole formed in stellar collisions in the super star cluster MGG 11. The x-ray flux from M82 is modulated, with a peak-to-peak amplitude corresponding to an isotropic luminosity of 2.4 _ 1040 erg s-1 in M82 and a period of 62.0 +/- 2.5 days, which we interpret as the orbital period of the ULX binary. This orbital period implies that the mass-donor star must be a giant or supergiant. Large mass-transfer rates, sufficient to fuel the ULX, are expected for a giant-phase mass donor in an x-ray binary. The giant phase has a short lifetime, indicating that we see the ULX in M82 in a brief and unusual period of its evolution.

X‐Ray Emission from the Nearby PSR B1133+16 and Other Old Pulsars

We detected a nearby (d=360 pc), old (5 Myr) pulsar B1133+16 with Chandra. The observed pulsar's flux is $(0.8\pm 0.2)\times 10^{-14}$ ergs cm$^{-2}$ s$^{-1}$ in the 0.5-8 keV band. Because of the small number of counts detected, the spectrum can be described by various models. A power-law fit of the spectrum gives a photon index $\Gamma = 2.5$ and an isotropic luminosity of $1.4\times 10^{29}$ ergs s$^{-1}$ in the 0.5-8 keV band, which is about $1.6\times 10^{-3}$ of the spin-down power $\dot{E}$. The spectrum can also be fitted by a blackbody model with a temperature of $\approx 2.8$ MK and a projected emitting area of $\sim 500$ m$^2$, possibly a hot polar cap. The X-ray properties of PSR B1133+16 are similar to those of other old pulsars observed in X-rays, particularly the drifting pulsar B0943+10.

Classifying the Zoo of Ultraluminous X-ray Sources

Ultraluminous X-ray sources (ULXs) are likely to include different physical types of objects. We discuss some possible subclasses, reviewing the properties of a sample of ULXs recently observed by Chandra and XMM-Newton. Sources with an isotropic X-ray luminosity up to a few times 1039 erg s-1 are consistent with normal stellar-mass X-ray binaries (mostly high-mass X-ray binaries in star-forming regions). Higher black hole (BH) masses (≈ 50–100M☉) may be the end product of massive stellar evolution in peculiar environments: they may explain ULXs with luminosities ≈ 1–2 × 1040 erg s-1. Only a handful of ULXs require a true intermediate-mass BH (M 500M☉). Finally, a small subclass of ULXs shows flaring or rapid variability in its power-law spectral component.

Strong correlation between the peak power density in the time domain and the luminosity of long γ-ray bursts

This work presents a possible luminosity estimator for long γ-ray bursts (GRBs) based on their light curves. We use the method of variability analysis in the time domain to calculate the power density spectrum (PDS) for each of the 12 GRBs with known redshifts observed by CGRO/BATSE. The peak of the power density spectrum P is a measure of the intensity of variability of the given light curve and a strong correlation is found between P and the isotropic peak luminosity L of the GRB. It is a successor to the lag-luminosity relation of Norris et al. (2000) and the variability-luminosity relation of Reichart et al. (2001).

ChandraStudy of X‐Ray Point Sources in the Early‐Type Galaxy NGC 4552 (M89)

We present a Chandra ACIS study of the early-type galaxy NGC 4552. We detect 47 X-ray point sources, most of which are likely low-mass X-ray binaries (LMXBs), within four effective radii (Re). The brightest X-ray source coincides with the optical, UV, and radio center of the galaxy and shows variability on >1 hr timescales, indicating the possible existence of a low-luminosity active galactic nucleus (AGN). The 46 off-center sources and the unresolved point sources contribute about 29% and 20% to the total luminosity of the galaxy, respectively. We find that after correcting for the incompleteness at the low-luminosity end, the observed cumulative X-ray luminosity function (XLF) of the off-center sources is best fitted by a broken power-law model with a break at Lb = 4.4 × 1038 ergs s-1. We identified 210 globular cluster (GC) candidates in a HST WFPC2 optical image of the galaxy's central region. Of the 25 off-center LMXBs that fall within the WFPC2 field of view, 10 sources are coincident with a GC. Thus, the fraction of the GCs hosting bright LMXBs and the fraction of the LMXBs associated with GCs are 4.8% and 40%, respectively. In the V and I bands, the GCs hosting bright LMXBs are typically 1-2 mag brighter than the GCs with no detected LMXBs. There are about 1.9 ± 0.4 times as many LMXBs in the red, metal-rich GCs as there are in the blue, metal-poor ones. We find no obvious difference between the luminosity distributions of LMXBs in GCs and in the field, but the cumulative spectrum of the LMXBs in GCs tends to be softer than that of the LMXBs in field. We detected three X-ray sources that have isotropic luminosities larger than 1039 ergs s-1. Only one of these is located in the joint Chandra-HST field and is found to be associated with a GC. By studying its ACIS spectra we infer that the this may be a candidate black hole system with a mass of 15-135 M☉. One of the other sources with a luminosity brighter than 1039 ergs s-1 reveals temporal variations in brightness on timescales greater than 1 hr.

On the Nature of the Ultraluminous X‐Ray Transient in Cen A (NGC 5128)

We combine nine ROSAT, nine Chandra, and two XMM-Newton observations of the Cen A galaxy to obtain the X-ray light curve of 1RXH J132519.8-430312 (=CXOU J132519.9-430317) spanning 1990-2003. The source reached a peak 0.1-2.4 keV flux FX > 10-12 ergs cm-2 s-1 during a 10 day span in 1995 July. The inferred peak isotropic luminosity of the source therefore exceeded 3 × 1039 ergs s-1, which places the source in the class of ultraluminous X-ray sources. Coherent pulsations at 13.264 Hz are detected during a second bright episode (FX > 3 × 10-13 ergs cm-2 s-1) in 1999 December. The source is detected and varies significantly within three additional observations but is below the detection threshold in seven observations. The X-ray spectrum in 1999 December is best described as a cutoff power law or a disk blackbody (multicolored disk). We also detect an optical source, mF555W ~ 24.1 mag, within the Chandra error circle of 1RXH J132519.8-430312 in Hubble Space Telescope images taken 195 days before the nearest X-ray observation. The optical brightness of this source is consistent with a late O or early B star at the distance of Cen A. If the optical source is the counterpart, then the X-ray and optical behavior of 1RXH J132519.8-430312 is similar to the transient Be/X-ray pulsar A0538-66.

Water-Vapor Maser Survey for Active Galactic Nuclei: A Megamaser in NGC 6926

Abstract We made a survey of water-vapor maser emission for 93 AGNs with the Nobeyama 45-m and Mopra 22-m telescopes from 1999 to 2002. A megamaser was detected in a Seyfert 2 galaxy, NGC 6926, at a distance of 80 Mpc, in 2002 June. [Greenhill et al. (2003a) have also reported a detection of the megamaser at the close date.] The peak flux density was 110 mJy, and the total isotropic luminosity was 340${L}_{\odot}$. The maser shows triply peaked spectrum, suggesting an edge-on disk. A narrow-line feature of the maser components at $V_{\mathrm{LSR}} = 6001 \,\mathrm{km} \,\mathrm{s}^{-1}$ was strongly variable with a time scale of a few tens of days, and the variation should be of intrinsic origin. We also showed a possibility of variability of water-vapor maser emission of a megamaser previously detected in a Seyfert/ultraluminous FIR galaxy, NGC 6240.

Extremely Luminous Water Vapor Emission from a Type 2 Quasar at Redshift z = 0.66

A search for water masers in 47 Sloan Digital Sky Survey type 2 quasars using the Green Bank Telescope has yielded a detection at a redshift of z = 0.660. This maser is more than an order of magnitude higher in redshift than any previously known and, with a total isotropic luminosity of 23,000 L☉, also the most powerful. The presence and detectability of water masers in quasars at z ~ 0.3-0.8 may provide a better understanding of quasar molecular tori and disks, as well as fundamental quasar and galaxy properties such as black hole masses. Water masers at cosmologically interesting distances may also eventually provide, via direct distance determinations, a new cosmological observable for testing the reality and properties of dark energy, currently inferred primarily through Type 1a supernova measurements.

High-resolution observations of SN 2001gd in NGC 5033

We report on 8.4 GHz VLBI observations of SN2001gd in the spiral galaxy NGC5033 made on 26 June 2002 and 8 April 2003. Our data nominally suggests a relatively strong deceleration for the expansion of SN2001gd, but we cannot dismiss the possibility of a free supernova expansion. From our VLBI observations on 8 April 2003, we inferred a minimum total energy in relativistic particles and magnetic fields in the supernova shell of E_min =(0.3-14) 10^{47} ergs, and a corresponding equipartition average magnetic field of B_min = (50--350) mG. We also present multiwavelength VLA measurements of SN2001gd, which are well fit by an optically thin, synchrotron spectrum, partially absorbed by thermal plasma. We obtain a supernova flux density of (1.02 +/- 0.05) mJy at the observing frequency of 8.4 GHz for the second epoch, which results in an isotropic radio luminosity of (6.0 +/- 0.3) * 10^{36} ergs between 1.4 and 43.3 GHz, at an adopted distance of 13.1 Mpc. Finally, we report on an XMM-Newton X-ray detection of SN2001gd on 18 December 2002. The supernova X-ray spectrum is consistent with optically thin emission from a soft component (associated with emission from the reverse shock) at a temperature around 1 keV. The observed flux corresponds to an isotropic X-ray luminosity of L_X = 1.4 +/- 0.4 * 10^{39} ergs/s in the (0.3-5) keV band. We suggest that both radio and X-ray observations of SN2001gd indicate that a circumstellar interaction similar to that displayed by SN1993J in M81 is taking place.

New H$_\mathsf{2}$O masers in Seyfert and FIR bright galaxies

Using the Effelsberg 100-m telescope, detections of four extragalactic water vapor masers are reported. Isotropic luminosities are ∼50, 1000, 1 and 230 Lfor Mrk 1066 (UGC 2456), Mrk 34, NGC 3556 and Arp 299, respectively. Mrk 34 contains by far the most distant and one of the most luminous water vapor so far reported in a Seyfert galaxy. The interacting system Arp 299 appears to show two maser hotspots separated by approximately 20 �� . With these new results and even more recent data from Braatz et al. (2004, ApJ, 617, L29), the detection rate in our sample of Seyferts with known jet-Narrow Line Region interactions becomes 50% (7/14), while in star forming galaxies with high (S 100 µm > 50 Jy) far infrared fluxes the detection rate is 22% (10/45). The jet-NLR interaction sample may not only contain jet-masers but also a significant number of accretion disk-masers like those seen in NGC 4258. A statistical analysis of 53 extragalactic H2O sources (excluding the Galaxy and the Magellanic Clouds) indicates (1) that the correlation between IRAS Point Source and H2O luminosities, established for individual star forming regions in the galactic disk, also holds for AGN-dominated megamaser galaxies; (2) that maser luminosities are not correlated with 60 µm/100 µm color temperatures; and (3) that only a small fraction of the luminous (LH2O > 100 L� ) detectable with 100-m sized telescopes have so far been identified. The H2O luminosity function (LF) suggests that the number of galaxies with 1 L� < LH2O < 10 L� , the transition range between kilomasers (mostly star formation) and megamasers (active galactic nuclei), is small. The overall slope of the LF, ∼−1.5, indicates that the number of detectable masers is almost independent of their luminosity. If the LF is not steepening at very high maser luminosities and if it is possible to find suitable candidate sources, H2O at significant redshifts should be detectable even with present day state-of-the-art facilities.

Ultrahigh energy cosmic rays from gamma ray bursts: implications of the recent observational results by Milagro

It has been speculated earlier that gamma ray bursts are sources of ultrahigh energy cosmic rays. Recently, the search for high energy photons from Gamma Ray Bursts by Milagro group has put limits on the isotropic luminosity of these transient sources in very high energy photons. The implications of the results obtained by Milagro to our understanding of the ultrahigh energy cosmic ray spectrum from these sources have been discussed in the present work.

Newly detected H2O Masers in Seyfert and Starburst Galaxies

AbstractWe report new detections of three H2O megamasers and one kilomaser using the Effelsberg 100-m telescope. Isotropic luminosities are ~50, 300, 1, and 230 L⊙ for Mrk 1066, Mrk 34, NGC 3556, and Arp 299, respectively. Mrk 34 contains the most distant H2O megamaser ever detected in a Seyfert. Our targets in this survey were chosen to fit one of the following criteria: 1) to have a high probability of interaction between the radio jet and the ISM within the central few parsecs of the radio galaxy, yielding masers which arise in local molecular clouds; or 2) to have very bright IRAS sources in which massive star forming regions might yield powerful masers. The ‘jet maser’ sources can provide detailed information about the conditions in the ISM in the central 1-10 pc of AGN. The extra-galactic ‘star formation masers’ can be used to pinpoint and characterize locations of high mass star formation in nearby galaxies. In addition, these sources will help to provide a better understanding of the chemical properties of molecular clouds in extra-galactic systems.

ChandraDetection of a Synchrotron Nebula around the Vela‐like Pulsar J1016−5857

We report on a 19 ks observation of the pulsar J1016-5857 with the Chandra X-Ray Observatory. This Vela-like pulsar has rotation period 107 ms, characteristic age 21 kyr, and spin-down power 2.6 × 1036 ergs s-1. A relatively bright, centrally peaked source of radius ≈25'' around the radio pulsar position has a spectrum that is well fitted by an absorbed power law with photon index 1.32 ± 0.25. We regard this as a newly identified pulsar wind nebula (PWN) that we designate PWN G284.0-1.8. We do not detect the pulsar as either a point X-ray source or a pulsed source in a 55 ks observation with the Rossi X-Ray Timing Explorer. The isotropic PWN luminosity is 3 × 1032 ergs s-1 in the 2-10 keV range, for a distance of 3 kpc that is consistent with the measured neutral hydrogen column density. The unpulsed flux from the pulsar is less than 30% of the measured PWN flux. The brightest component of the PWN, near the pulsar, shows extended emission of size ~2'' that may indicate, by analogy with other young pulsars, the wind termination shock. In the Chandra image we also detect a very faint extended structure ≈1' × 2' in size that is highly asymmetric about the pulsar position. This structure is a good match in width and position angle to the tip of a finger of radio emission that appears to connect to the nearby supernova remnant G284.3-1.8, but we cannot characterize it further with the available data. There is a variable X-ray point source only 15 from the pulsar, which we identify using optical spectroscopy as an accreting binary.